Principles and Concepts Level B 3.0

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According to the balanced equation 10HI+2KMnO4+3H2SO4=5Ix+2MnSO4 +K2SO4+8H20, how many moles of HI would be necessary to produce 2.5 mole of I2, starting with 4.0 mole of KMnO4and 3.0 mole of H2SO4? Select a Choice Below current question choicesOptionA20 moleOptionB10 moleOptionC5 moleOptionD2.5 mole

(C) 5 mole EXPLANATION 2.5 moles of I2 would be half of a recipe, so you would need half as much HI as well. (1/2)(10) = 5 moles.

What is a mixture? Select a Choice Below current question choicesOptionAMade of two or more elements joined together by a chemical force.OptionBA solution that can only be separated by chemical means.OptionCA combination of two or more substances not chemically combined.OptionDA solution consisting of two or more chemical substances.

(C) A combination of two or more substances not chemically combined. EXPLANATION A mixture contains two or more substances that are not chemically combined.

If the following reaction is a double replacement, what will be the products formed? AgCl3+AgNO3=

(C) Al(NO3)3+3AgCl EXPLANATION The positive 3+ ion in aluminum is attracted to the 1- nitrate ion, and the 1+ ion in silver is attracted to the 1- chloride ion.

What is an isotope? Select a Choice Below current question choices OptionAAn atom that has the same number of neutrons as other atoms of the same element but different number of protons OptionBAn atom that has the same number of electrons as other atoms of the same element but different number of protons OptionCAn atom that has the same number of protons as other atoms of the same element but different number of neutrons OptionDAn electron shell where atoms jump from level to level

(C) An atom that has the same number of protons as other atoms of the same element but different number of neutrons EXPLANATION An isotope is each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.

Heat is the: Select a Choice Below current question choices OptionA Total amount of energy contained in an object. OptionB Energy transferred between objects because of a temperature difference. OptionC Average amount of energy per molecule contained in an object OptionD All of the above

(C) Average amount of energy per molecule contained in an object EXPLANATION Heat determines the average kinetic energy of the atoms making up the substance.

Temperature is mostly related to: Option A Average energy of a substance. Option B The total kinetic energy an object has. Option C Average molecular kinetic energy in a substance. Option D Total kinetic energy an object has.

(C) Average molecular kinetic energy in a substance. EXPLANATION The temperature of a gas measures the average kinetic energy of the molecules that make up the gas sample.

A compound contains 24 g of carbon and 8 g of hydrogen. (atomic masses are 12 u for carbon and 1 u for hydrogen) What is the empirical formula for the compound? Select a Choice Below current question choices OptionA CH OptionB CH2 OptionC CH4 OptionD C2H8

What is the formula for the compound formed by Ca2+ calcium ions with Cl- chloride ions? Select a Choice Below current question choices OptionA CaCl OptionB Ca2Cl OptionC CaCl2 OptionD CaCl3

A science that examines the material contained in the universe and the changes that take place in them is called: Select a Choice Below current question choices OptionA Physics OptionB Biology OptionC Chemistry OptionD Geography

Which of the following contributes to an overload of the carbon cycle? Select a Choice Below current question choices OptionA Photosynthesis OptionB Cellular respiration OptionC Deforestation OptionD All of the above

(C) Deforestation EXPLANATION Deforestation has an effect on the Carbon Cycle also known as the Greenhouse gas effect and global warming. Trees and forest balance the amount of Carbon in the atmosphere through the process of photosynthesis in which plants make their own food with carbon dioxide.

hat would be the best name for B2S3? Select a Choice Below current question choicesOptionABeryllium sulfideOptionBBoron SulfideOptionCDiboron TrisulfideOptionDDiboron Trisulfate

(C) Diboron Trisulfide EXPLANATION When two nonmetallic elements form a molecular compound, the naming convention specifies the two elements, but with added prefixes to specify the numbers of atoms of each element.

The reaction AlCl3+3NaOH=Al(OH)3+3NaCl is an example of what kind of chemical reaction? Select a Choice Below current question choices OptionADecomposition OptionBSingle replacement OptionCDouble replacement OptionDCombination

(C) Double replacement EXPLANATION A double replacement reaction is a type of reaction that occurs when the cations and anions switch between two reactants to form new products.

Which compound's name includes the Greek numerical prefixes di- and tri-? Select a Choice Below current question choices OptionA Fe2O3 OptionB Ca3(PO4)2 OptionC N2O3 OptionD Al2S3

(C)N2O3 EXPLANATION Look for elements that form a molecular (covalent) bond. The naming rules require specifying the number of each type of atom with a prefix.

Which of the following would be most significant in understanding the structure of an ecological community? Select a Choice Below current question choices OptionA Determining which particular species are present OptionB Determining the kinds of interactions that occur among organisms of different species OptionC Determining the relative abundance of species OptionD All of the above

(D) All of the above

What should you do to convert from °C to °F? Select a Choice Below current question choices OptionA Add 32 to C, then multiply by 9/5. OptionB Subtract 32 from C, then multiply by 5/9. OptionC Multiply C by 5/9, then subtract 32. OptionD Multiply C by 9/5, then add 32.

(D) Multiply C by 9/5, then add 32.

A scientist weights out 45g of copper wire, and later determines that the sample has a volume of 5cm3. What is the density of that sample of copper wire? Select a Choice Below current question choices OptionA. 1/9 g/cm3 OptionB. 5g/cm3 OptionC. 9g/cm3 OptionD. 225g/cm3

9g/cm3

Which of the following is most likely to occur during the development of photochemical smog on a typical hot, sunny day in a big city? Select a Choice Below current question choices OptionA Ozone reaches its peak concentration around 8 a.m. OptionB Nitrogen dioxide reaches its peak concentration around 3 p.m. OptionC Ozone reaches its highest concentration in the late afternoon. OptionD Nitric oxide reaches its lowest concentration around 12 noon.

C) Ozone reaches its highest concentration in the late afternoon.

As a double replacement reaction, what would be the products formed by this reaction CaCl2+Na2CO3? Select a Choice Below current question choices OptionA CaCO3+2NaCl OptionB CaCO3+NaCl OptionC Na)3+CaNaCl OptionD CaNaC+O3Cl

A) CaCO3+2NaCl

An association between two individuals or populations where both benefit and where neither can survive without the other is called: Select a Choice Below current question choicesOptionACompetitionOptionBCommensalismOptionCMutualismOptionDProtocoperation

C) Mutualism

Which of the following refers to aquifers that are regularly replenished by snowmelt? Select a Choice Below current question choices OptionA Semi-arid region OptionB Proved water reserve OptionC Renewable groundwater OptionD Secure landfill

C) Renewable groundwater

Which of the following refers to densely populated urban areas marked by crowding, substandard housing, poverty, and social disorganization? Select a Choice Below current question choices OptionA Abyssal zones OptionB Steppes OptionC Slums OptionD Cities`

C) Slums

Which term do ecologists use to describe the ability of a community either to resist change or to recover to its original state after change? Select a Choice Below current question choices OptionA Stability OptionB Succession OptionC Partitioning OptionD Productivity

(B) Succession EXPLANATION Ecological succession is the process of change in the species structure of an ecological community over time.

Which of the following will most likely happen to a predator population if its prey population decreases? Select a Choice Below current question choices OptionA There will be no change in the predator population. OptionB There will be a decrease in the predator population over time. OptionC There will be an increase in the predator population over time. OptionD There will be an immediate extinction of the predator population.

(B) There will be a decrease in the predator population over time.

All of the following are reasons for urbanization except: Select a Choice Below current question choices OptionA Rent is more affordable in urban areas. OptionB Urban areas have better healthcare and educational facilities. OptionC There are more jobs available in urban areas. OptionD There are more opportunities for entertainment in urban areas.

(B) Urban areas have better healthcare and educational facilities. EXPLANATION Urban areas may have cheaper rent, more job opportunities and more things to do for entertainment, but in general, health care and educational facilities are older, poorer equipped and not as well staffed.

How is the Celsius temperature scale defined? Select a Choice Below current question choices OptionAA temperature scale where 32° is the freezing point of water and 212° is the boiling point. OptionBA temperature scale where 0° is the freezing point of water and 100° is the boiling point. OptionCA temperature scale where 212° is the freezing point of water and 32° is the boiling point. OptionDA temperature scale where 100° is the freezing point of water and 0° is the boiling point.

(B)A temperature scale where 0° is the freezing point of water and 100° is the boiling point.

Would you normally expect neon (Ne) to form compounds? Select a Choice Below current question choices OptionA Yes, but neon is a rare gas and difficult to obtain. OptionB No, neon needs six electrons to fill its outermost levl. OptionC Yes, neon needs six valence electrons to fill its outermost energy level. OptionD No, neon has eight valence electrons in its outermost levl and is stable.

(D) No, neon has eight valence electrons in its outermost levl and is stable.

Which of the following atoms is the largest? Select a Choice Below current question choices OptionA B OptionB Al OptionC Ca OptionD Rb

(D) Rb

Combustion reactions always: Select a Choice Below current question choices OptionAUse only one reactant. OptionBForm only one product. OptionCInvolve an element and an ionic compound. OptionDRequire oxygen gas.

(D) Require oxygen gas.

A caterpillar eats a leaf, and a bird eats the caterpillar. In this interaction, the bird is a: Select a Choice Below current question choices OptionA Producer OptionB Herbivore OptionC Primary consumer OptionD Secondary consumer

(D) Secondary consumer

The reaction Fe+H2SO4=H2+FeSO4 is an example of what kind of chemical reaction? Select a Choice Below current question choices OptionADouble replacement OptionBCombination OptionCDecomposition OptionDSingle replacement

(D) Single replacement

Which of the following metals is more reactive than the others? Select a Choice Below current question choicesOptionACopperOptionBCalciumOptionCAluminumOptionDSodium

(D) Sodium

Which of the following collects and distributes Earth's fixed supply of water through the processes of evaporation, evapotranspiration, and precipitation? Select a Choice Below current question choices OptionA The hydrofracturing process OptionB The ecological process OptionC The oxidation cycle OptionD The hydrological cycle

(D) The hydrological cycle

Which statement about enthalpy is true? Select a Choice Below current question choicesOptionAHeat is given off to the surroundings in endothermic reactions.OptionBSome substances have a negative specific heat capacity.OptionCSpecific heat capacity is the same for all liquids.OptionD The sign of delta H is always negative in exothermic reactions.

(D) The sign of delta H is always negative in exothermic reactions.

Which biome is characterized by a layer of permafrost? Select a Choice Below current question choicesOptionATaigaOptionBSavannaOptionCChaparralOptionDTundra

(D) Tundra

Fracking: Select a Choice Below current question choices OptionA Is an environmentally benign process. OptionB Is a relatively inexpensive way to extract fossil fuels OptionC Uses water to fracture rocks and recover gas OptionD Uses water and chemicals to fracture rocks and recover gas

(D) Uses water and chemicals to fracture rocks and recover gas

How many grams of O2 (molar mass 32 g/mole) are needed to completely react with 136 g of NH3 (molar mass 17 g/mole)? OptionA 160 g OptionB 216 g OptionC 256 g OptionD 320 g

(D) 320 g EXPLANATION 8 moles of NH3 are needed, so 10 moles of H2O are needed. Therefore, (10 moles)(36 g/mole) = 360 grams are needed.

Consider the balanced equation N2+3H2=2NH3. When 4.50 moles of H2 react, how many grams of N2 are needed? Molar masses are 14 g (nitrogen) and 1 g (hydrogen). Select a Choice Below current question choicesOptionA28.0 gOptionB14.0 gOptionC28.5 gOptionD42.0 g

(D) 42.0 g EXPLANATION 4.5 moles of hydrogen will need 1.5 moles of nitrogen gas, so (1.5)(28 g/mole) = 42 g/mole.

The high levels of pesticides in birds of prey is an example of: Select a Choice Below current question choices OptionA The principle of exclusion OptionB Cycling of nutrients by decomposers OptionC Biological magnification OptionD Ecological succession

Why is plastic dangerous for marine life? Select a Choice Below current question choices OptionA They mistake it for food and cannot digest it. OptionB They get tangled in it which hinders their ability to swim. OptionC Both a and b responses OptionD It's not dangerous because they use plastic waste for their habitat.

According to the theory of demographic transition, a country in Phase 1 demographic transition will experience which of the following? Select a Choice Below current question choices OptionA Declining population growth OptionB Stable population growth OptionC Slow population growth OptionD No population growth

Which would cause a more serious burn: 30 g of steam or 30 g of liquid, both at 100 degrees C and why is this so? Select a Choice Below current question choices OptionA Water, because it is denser than steam. OptionB Steam, because of its specific heat capacity. OptionC Steam, because of its latent heat of vaporization. OptionD Water, because its specific heat is greater than that of steam.

What is the reason for the yellow color in smog? Select a Choice Below current question choices OptionA Nitrogen dioxide OptionB Sulfur dioxide OptionC Sulfate ions OptionD Nitrate ions

What is the source of carbon in fossil fuels? Select a Choice Below current question choices OptionA Combustion and respiration OptionB Carbon captured during nitrogen fixation OptionC The buried remains of long-dead organisms OptionD Carbon dioxide in ground water

Nuclear fusion involves: Select a Choice Below current question choices OptionA The splitting of the atomic nuclei OptionB The splitting of the atomic electrons OptionC The combining of atomic nuclei OptionD The combining of atomic electrons

What information in the Periodic Table indicates the number of protons in an atom? Select a Choice Below current question choicesOptionAThe position of the element in its columnOptionBThe element's chemical symbolOptionCThe element's atomic numberOptionDThe element's atomic mass

Where is the part of the periodic table that is collectively referred to as the s block located? Select a Choice Below current question choicesOptionAThe last two columns of the periodic tableOptionBThe left-most six rows of the periodic tableOptionCThe first two columns of the periodic tableOptionDThe right-most six columns of the periodic table

The IPAT equation was developed to estimate the: Select a Choice Below current question choices OptionA affluence of a country's population. OptionB The rate of demographic transition. OptionC The impact of human lifestyles on Earth. OptionD The effect of urbanization on resource use.

What is an atom? Select a Choice Below current question choices OptionAA substance capable of dissolving another substance OptionBThe cell organelle that houses the cell's DNA OptionCThe smallest and the most fundamental unit of matter OptionDA type of lipid composed of four fused hydrocarbon rings

Which of the following statements about tropical rainforests is false?

Chlorine radicals in the stratosphere acts as catalysts for the following reaction: O3+O-=2O2. Which statement is true about the action of the chlorine molecules? Select a Choice Below current question choices OptionA They increase the number of collisions between ozone molecules and oxygen molecules. OptionB They act as heterogeneous catalysts. OptionC They are not used up in the process. OptionD They increase the energy of the collisions.

The correct Lewis dot diagram for the oxygen atom has: Select a Choice Below current question choices OptionA One lone pair of valence electrons and one bonding site. OptionB Two lone pairs of valence electrons and one bonding site. OptionC Two lone pairs of valence electrons and two bonding sites. OptionD Three lone pairs of valence electrons.

Biodiversity can be defined as: Select a Choice Below current question choices OptionA Number of plants in a habitat OptionB Number of animals in a habitat OptionC Variety of species in an ecosystem OptionD Plants and animals together with their habitat

Which of the following is not a physical characteristic that is used to identify an element? Select a Choice Below current question choices OptionAMelting point OptionBBoiling point OptionCVolume OptionDDensity

If the following reaction is a single replacement, what will the reaction be when it is completely balanced Ba+HCl?

2Ba+2HCl=H2+2BaCl EXPLANATION The number of each type of atom contained in the reactants must be the same as the number of each type of atom included in the products.

Identify the one reaction listed below that best describes a reaction that contributes to the formation of ground-level photochemical smog.

2NO+O2=2NO2

The atom whose outermost shell structure (principal energy level) most closely resembles that of neon (atomic number 10) has which of the following atomic numbers? Select a Choice Below current question choices OptionA 11 OptionB 16 OptionC 18 OptionD 31

(C) 18 EXPLANATION Neon is a noble gas with its outermost electron orbitals completely filled. The next noble gas is argon, having atomic number 18, and it has a very similar structure to that of neon.

What is the molecular mass of a water molecule, H2O? (atomic masses are 1 u for hydrogen, 16 u for oxygen) Select a Choice Below current question choicesOptionA2 uOptionB16 uOptionC18 uOptionD36 u

(C) 18 u EXPLANATION The atomic mass for oxygen and hydrogen are 16 and 1 u, respectively. The molecular formula for water is H2O . Therefore, the atomic mass for water is 16 + 1 + 1 = 18 u.

The Kinetic-Molecular theory predicts that pressure rises as the temperature of a gas increases because: Select a Choice Below current question choicesOptionAThe average kinetic energy of the molecules decreases.OptionBThe gas molecules collide less frequently with the wall.OptionCThe gas molecules collide less energetically with the wall.OptionDThe gas molecules both collide more frequently with the wall and collide more energetically with the wall.

D) The gas molecules both collide more frequently with the wall and collide more energetically with the wall.

The cycling of water through the hydrologic cycle depends on: Select a Choice Below current question choices OptionA Transpiration from plants. OptionB Evaporation from the soil. OptionC Precipitation to the ocean OptionD All of the above

D) All of the above

All of the following are renewable energy sources except: Select a Choice Below current question choices OptionA Wind OptionB Solar power OptionC Biofuels OptionD Deep-earth geothermal energy

D) Deep-earth geothermal energy

Which of the following exists as a molecule in its natural state? Select a Choice Below current question choices OptionAPotassium OptionBSodium OptionCCarbon OptionDOxygen

D) Oxygen

Pick the characteristic feature of species that are generalists. Select a Choice Below current question choices OptionA They cannot kill and eat large sized prey. OptionB They have a highly specialized diet. OptionC They include the northern spotted owls that live in cavities of trees. OptionD They can survive on diverse types of prey.

D) They can survive on diverse types of prey.

The empirical formula of a substance is COH2. (atomic masses are 12 u for carbon, 16 u for oxygen and 1 u for hydrogen) The molar mass of the substance is 120 g. What is the molecular formula of the same substance? Select a Choice Below current question choices OptionA COH2 OptionB C3O5H4 OptionC C3O3H6 OptionD C4O4H8

D) C4O4H8 EXPLANATION The molecular mass of COH2 is 30 u, so you need four times as many of each kind of atom.

Which of the following is true of demographic transition? Select a Choice Below current question choices OptionA Rapid population growth is characteristic of Phase 1. OptionB Phase 2 is characterized by low birth rates and high death rates. OptionC Phase 1 is characterized by low birth rates and low death rates. OptionD Rapid population growth occurs during Phase 2.

D) Rapid population growth occurs during Phase 2. EXPLANATION Phase 2 features a dramatic drop-off in the death rate, which creates rapid increase in the overall population.

Which of the following contains the reactants needed for forming acid rain? current question choices OptionA SO2+H20+NO4 OptionB SO4+H20+NO OptionC SO2+H20+CO2 OptionD SO2+H20+NO

D)SO2+H20+NO EXPLANATION Acid rain predominantly starts with either sulfur dioxide or nitric oxide reacting with atmospheric vapor to produce sulfurous acid, sulfuric acid or nitric acid.

Pick the statement that accurately differentiates r-selected and K-selected organisms. Select a Choice Below current question choices OptionA r-selected species are less prone to extinction than K-selected species. OptionB Unlike K-selected organisms that grow rapidly, r-selected organisms grow more slowly. OptionC r-selected organisms tend to be large, whereas K-selected organisms tend to be small. OptionD Unlike r-selected organisms, K-selected organisms adapt to unstable environments.

r-selected species are less prone to extinction than K-selected species.

Most halogens form compounds by:

gaining an electron to form a negative ion

Covalent bonds are formed between:

nonmetal atoms

Which of the following scenarios best describes the great extinction events? Select a Choice Below current question choices OptionA 70-95% of the species present on the planet become extinct OptionB 70-95% of the population of a particular species die off OptionC 25-45% of the species present on the planet die in significant numbers at once OptionD 75% of the species on the planet suffer major population loss

(A) 70-95% of the species present on the planet become extinct

Which property shows an increasing trend across a period of the Periodic Table? Select a Choice Below current question choicesOptionAElectronegativityOptionBAtomic radiusOptionCMetallic characterOptionDReactivity

(A) Electronegativity

The size of atoms generally increases as you move down the Periodic Table because: Select a Choice Below current question choicesOptionAThe electron orbitals get bigger.OptionBThe nucleus gets heavier.OptionCThere are more electrons.OptionDMore neutrons are needed for stability.

(A) The electron orbitals get bigger. EXPLANATION Atomic radius increases from top to bottom within a group. This is caused by electron shielding. As the atomic radii increases down the group, orbitals in the atom keeps increasing.

Which one of the following statements about p orbitals is incorrect? Select a Choice Below current question choices OptionA They are found in all principal energy levels. OptionB They have a dumbbell shape. OptionC There are 3 types of p orbitals. OptionD Each p orbital can hold up to two electrons.

(A) They are found in all principal energy levels. EXPLANATION There are 3 types of p orbitals, each of which can hold a maximum of 2 electrons, and each p orbital has a dumbbell shape. You don't find p orbitals in the first principal energy level (Level 1).

All of the following substances are derived from petroleum except: Select a Choice Below current question choices OptionA Asphalt OptionB Cellulose OptionC Polystyrene OptionD Nylon

(B) Cellulose

Sulfur dioxide is a: Select a Choice Below current question choices OptionA Yellow-brown gas that contributes to photochemical smog. OptionB Colorless gas that smells like a burnt match and damages the lungs. OptionC Gas with a "rotten egg" smell that is highly toxic and corrosive. OptionD Reactive gas produced, in part, by photochemical reaction of sunlight with various air pollutants.

(B) Colorless gas that smells like a burnt match and damages the lungs.

The main environmental effects of ozone depletion could include all of the following except: Select a Choice Below current question choices OptionA Lower food-crop production. OptionB Decreased concentration of CO2 in the atmosphere. OptionC Disruption of marine food chains. OptionD Increased incidence of skin cancer.

(B) Decreased concentration of CO2 in the atmosphere.

Identify the category of accessible runoff available to meet human water needs. Select a Choice Below current question choices OptionA Seawater that is desalinated OptionB Floodwater stored in reservoirs OptionC In-place water resources OptionD Groundwater that is nonrenewable

(B) Floodwater stored in reservoirs

What is the only way to stabilize the size of a population?

(B) Reaching the replacement fertility rate

If the following reaction is a single replacement, what products will form in the balanced equation? Ba+HCl=? Select a Choice Below current question choices OptionA BaH2+Cl2 OptionB H2BaCl2 OptionC 2H+BaCl2 OptionDH2+2BaCl

(B) H2+BaCl2 EXPLANATION Barium has a 2+ ionic charge and chloride has a 1- ionic charge. Therefore, they will be motivated to form barium chloride, BaCl2 . The hydrogen reforms as diatomic hydrogen molecules.

A country with an age structure like the one shown here will experience: Select a Choice Below current question choices OptionA A rapidly growing population OptionB Stable population growth OptionC A decline in population OptionD High life expectancy

(B) Stable population growth EXPLANATION There are two ways to view this age structure diagram. Both males and females show a normal distribution among age groups, which would normally happen under stable conditions. Also, the number of newborns approximates the number of elderly, so without a catastrophe, the populations should remain stable.

How is chemistry defined as a scientific endeavor? Select a Choice Below current question choices OptionA Study and practice of making basic materials OptionB Study of substances, their properties and interactions OptionC Study of the interaction of matter with energy OptionD Study of the emotional or psychological interactions between people

(B) Study of substances, their properties and interactions EXPLANATION Webster defines chemistry as "a science that deals with the structure and properties of substances and with the changes that they go through."

Some bacteria have the ability to "fix" nitrogen. This means: Select a Choice Below current question choices OptionA They convert ammonia into nitrites and nitrates. OptionB They convert atmospheric nitrogen gas into biologically useful forms of nitrogen. OptionC They break down nitrogen-rich compounds and release ammonium ions. OptionD They convert nitrate into nitrogen gas.

(B)They convert atmospheric nitrogen gas into biologically useful forms of nitrogen.

A demographic transition is typical of: Select a Choice Below current question choices OptionA A country that has undergone a population crisis due, for example, to epidemics, war or famine OptionB A developed country OptionC A country whose birth and death rates are shifting as it moves from the primitive to the modern condition OptionD A developing country

What is the best description for 'enthalpy change'? Select a Choice Below current question choicesOptionAIt is the volume of a substance divided by its cross-sectional area.OptionBIt is the product of volume and cross-sectional area of a substance.OptionCIt is the heat of a process when pressure is held constant.OptionDIt is a substance's mass divided by its volume.

If the temperature of a fixed quantity of gas decreases and the pressure remains unchanged: Select a Choice Below current question choicesOptionAIts volume increases.OptionBIts volume is unchanged.OptionCIts volume decreases.OptionDIts density decreases.

Which of the following is not a cause for biodiversity loss?

What is causing the crisis in biodiversity in the world? Select a Choice Below current question choices OptionA Pollution of ecosystems OptionB Conservation of species diversity OptionC Loss of habitats OptionD Deforestation

How might a lack of sunlight disrupt the food web? Select a Choice Below current question choices OptionA It would cause consumers to consume less. OptionB It would prevent decomposers from decomposing matter. OptionC It would prevent producers from producing nutrients. OptionD It would not disrupt the food web at all.

What should you do to convert from °F to °C? Select a Choice Below current question choices OptionAMultiply F by 5/9, then subtract 32. OptionBAdd 32 to F, then multiply by 5/9. OptionCSubtract 32 from F, then multiply by 5/9. OptionDMultiply F by 5/9, then add 32.

(C) Subtract 32 from F, then multiply by 5/9. EXPLANATION The formula for converting from Fahrenheit to Celsius is: C = (5/9)(F - 32).

Chlorine as atomic number 17. A neutral atom of the 37 Cl isotope has: Select a Choice Below current question choices OptionA37 protons, 37 neutrons, and 37 electrons OptionB17 protons, 37 neutrons, and 17 electrons OptionC17 protons, 20 neutrons, and 37 electrons OptionD17 protons, 20 neutrons, and 17 electrons

(D) 17 protons, 20 neutrons, and 17 electrons EXPLANATION If an isotope has atomic number 17, then a neutral atom of that isotope will have 17 protons and 17 electrons. If the atomic mass number is 37, then the number of neutrons can be calculated by 37 - 17 = 20 neutrons.

Which statement about noble gases is correct? Select a Choice Below current question choicesOptionAThey form compounds with very bright colors.OptionBThey exist as single atoms rather than as molecules.OptionCThey are highly reactive with both metals and nonmetals.OptionDThey are extremely rare in nature.

(D) They are extremely rare in nature. EXPLANATION The noble gases are any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (18) of the periodic table.

Energy efficiency is defined as: Select a Choice Below current question choices OptionA Energy that escapes in a usable form. OptionB (Energy in bonds broken) - (Energy in bonds formed) OptionC The content of energy in a fossil fuel OptionD The amount of energy extracted from a system divided by the total energy you put into the system

(D)The amount of energy extracted from a system divided by the total energy you put into the system

What is the study of the four natural spheres of the Earth and all the complex interactions among them known as? Select a Choice Below current question choices OptionA Environmental science OptionB Biotechnology OptionC Evolutionary psychology OptionD Paleontology

A) Environmental science

Which of the following are the reserves of ice-encrusted natural gas found in porous rock? Select a Choice Below current question choices OptionA Mineral deposits OptionB Methane hydrates OptionC Oil shale deposits OptionD Tropic cascades

B) Methane hydrates

The atomic number is always equal to the total number of: Select a Choice Below current question choices OptionANeutrons in the nucleus OptionBProtons in the nucleus OptionCNeutrons plus protons in the nucleus OptionDProtons plus electrons in the atom

B) Protons in the nucleus

Which of the following actions would be the most effective in decreasing acid rain and acid deposition problems? Select a Choice Below current question choices OptionA Using higher smokestacks OptionB Reducing use of fossil fuels OptionC Developing acid-resistant crops OptionD Adding lime to acidified lakes

B) Reducing use of fossil fuels

What is the formula for diphosphorus pentoxide?

P2O5

Rutherford suggested a planetary model for the structure of an atom. Which of the following was not an assumption made by the Rutherford model of the atom? Select a Choice Below current question choicesOptionAElectrons revolve in circular orbits around the nucleus.OptionBThe nucleus consists of protons and neutrons.OptionCThe mass of the atom is concentrated in the nucleus.OptionDMost of the volume of an atom is empty space.

(B) The nucleus consists of protons and neutrons.

A gas that is confined in a rigid container is heated. Which of the following statements is true? Select a Choice Below current question choices OptionA The kinetic energy of the gas particles will decrease. OptionB The pressure will increase. OptionC The number of moles of gas will increase. OptionD The volume will increase.

(B) The pressure will increase.

Which of the following is not true of compounds? Select a Choice Below current question choicesOptionAThey contain two or more elements.OptionBThey form after a physical change.OptionCThey have their own physical properties.OptionDThey do not form randomly.

(B) They form after a physical change.

Ozone in the stratosphere is important to organisms at the earth's surface because ozone molecules are very strong absorbers of: Select a Choice Below current question choices OptionA Infrared rays OptionB Ultraviolet rays OptionC Microwave radiation OptionD Visible light

(B) Ultraviolet rays

Which of the following is not a characteristic of biomes? Select a Choice Below current question choices OptionA Includes a large area OptionB Uniform habitats OptionC A characteristic appearance OptionD A common climate

(B) Uniform habitats

An atom's mass number equals the number of: Select a Choice Below current question choices OptionAprotons plus electrons OptionBprotons plus neutrons OptionCprotons OptionDneutrons

(B) protons plus neutrons

How many moles are in 4 g of methane, ? The molar masses are 12 g (carbon) and 1 g (hydrogen). Select a Choice Below current question choices OptionA0.2 mole OptionB0.25 mole OptionC0.5 mole OptionD1.25 mole

(B) 0.25 mole EXPLANATION Mass divided by the molar mass of the substance determines the number of moles.

Determine the symbol for an isotope of carbon that has an atomic number of 6 and a mass number of 12. Select a Choice Below current question choices OptionA 14 C 6 OptionB. 12C 6 OptionC. 13C 6 OptionD None of the above

(B) 12C 6 EXPLANATION Isotopes like carbon-12 use a convention which specifies the mass number (on top) and the atomic number (on bottom), both in front of the chemical element symbol. Therefore, carbon-12 would have the atomic symbol 'C' with the numbers 12 and 6 preceding it and written one on top of the other.

Which of the following is the full electron configuration for a neutral atom of manganese (atomic number 25)?

(B) 1s*2-2s*2-2p*6-3s*2-3p*6-4s*2-3d*5 EXPLANATION The orbitals fill in the sequence 1s (2 electrons), 2s (2 electrons), 2p (6 electrons), 3s (2 electrons), 3p (6 electrons), 4s (2 electrons). The remaining 3 electrons must go into the 3d orbitals.

One type of copper wire has a density of 9g/cm3 . A scientist weighs 27 g out of wire. What would be the volume of that sample? Select a Choice Below current question choices OptionA 1/3 cm3 OptionB 3 cm3 OptionC 9 cm3 OptionD 243 cm3

(B) 3 cm3 EXPLANATION Density is the ratio between mass and volume, so the equivalent relationship is that volume equals mass divided by the density.

How many electrons are in the valence shell of a neutral phosphorus atom? (Phosphorus has atomic number 15.) Select a Choice Below current question choices OptionA 3 OptionB 5 OptionC 7 OptionD 13

(B) 5 EXPLANATION Phosphorus fills the 1s, 2s and 2p orbitals completely. It has 5 electrons remaining, so it must have 5 valence electrons.

How many electrons are in the valence shell of a neutral phosphorus atom? (Phosphorus has atomic number 15.) Select a Choice Below current question choicesOptionA3OptionB5OptionC7OptionD13

(B) 5 EXPLANATION Phosphorus fills the 1s, 2s and 2p orbitals completely. It has 5 electrons remaining, so it must have 5 valence electrons.

What is a molecule? Select a Choice Below current question choices OptionAThe smallest particle of an atom OptionBA group of atoms held together by chemical means OptionCA subatomic particle with a negative charge OptionDHas no charge and lives in the nucleus.

(B) A group of atoms held together by chemical means EXPLANATION Molecules are a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Which of the following is most likely to occur in a forested region that has recently been clear-cut? Select a Choice Below current question choices OptionA The concentration of nitrates in streams running through the region will increase. OptionB The average depth of the topsoil will increase. OptionC Volume of runoff after rains will decrease. OptionD The frequency of landslides will decrease.

(A) The concentration of nitrates in streams running through the region will increase.

When does the principal-agent problem occur? Select a Choice Below current question choices OptionA When one party makes decisions that will have a large impact on energy consumption, while another party actually pays the energy bills OptionB When one party makes important decisions that do not impact on energy consumption or another party's interest OptionC When one party makes decisions that will have a large impact on energy consumption, but another party refuse to follow that decision OptionD When two parties makes mutually beneficial decisions that will have a large impact on energy consumption

(A) When one party makes decisions that will have a large impact on energy consumption, while another party actually pays the energy bills

A temperature inversion is the result of: Select a Choice Below current question choices OptionA A lid of warm air on top of cooler air. OptionB Precipitation. OptionC A cold blanket of air that prevents warm air from rising. OptionD A steady decrease in air temperature with altitude.

(A) A lid of warm air on top of cooler air.

A country with a much greater number of younger people than older people has an age structure diagram that resembles which of the following? Select a Choice Below current question choices OptionA A pyramid OptionB A column OptionC An inverted pyramid OptionD A kite

(A) A pyramid

Which of the following is characterized by low annual rainfall and is subject to frequent and prolonged droughts? Select a Choice Below current question choices OptionA A semi-arid region OptionB A proved reserve OptionC An arctic tundra OptionD An aquatic biome

(A) A semi-arid region

Why is genetic diversity important?

(A) Allows for species to adapt to and thrive in different environments

What is meant by the term 'slash and burn'? Select a Choice Below current question choices OptionA An agricultural activity OptionB A form of urbanization OptionC A form of felony OptionD A form of social movement

(A) An agricultural activity

What is the focus of the Atomic Molecular Theory? Select a Choice Below current question choicesOptionAAtoms, matter, elements and compoundsOptionBProtons, neutrons, and electronsOptionCPositive and negative charges of atomsOptionDThe periodic table

(A) Atoms, matter, elements and compounds

Which statement is NOT true of biodiversity? Select a Choice Below current question choices OptionA Biodiversity decreases closer to the equator. OptionB Biodiversity is not evenly distributed on the planet. OptionC Biodiversity can be measured at a number of organizational levels. OptionD Biodiversity is greatest in the tropics.

(A) Biodiversity decreases closer to the equator.

Which two greenhouse gases found in the Earth's troposphere contribute most to the greenhouse effect? Select a Choice Below current question choices OptionA Carbon dioxide and water vapor OptionB Carbon dioxide and methane OptionC Carbon dioxide and ozone OptionD Methane and ozone

(A) Carbon dioxide and water vapor

The largest population an environment can support is its: Select a Choice Below current question choices OptionA Carrying capacity OptionB Limiting factor OptionC Population OptionD Symbiosis

(A) Carrying capacity

What is the study of the interactions of matter with other matter and with energy known as? Select a Choice Below current question choices OptionA Chemistry OptionB Geology OptionC Bibliography OptionD Oncology

(A) Chemistry

The chemical that is given off by CFC's and harmful to the ozone layer is: Select a Choice Below current question choices OptionA Chlorine OptionB Fluorine OptionC Sulfur dioxide OptionD Nitrogen peroxide

(A) Chlorine

The ozone layer of the upper atmosphere is being destroyed by: Select a Choice Below current question choices OptionA Chlorofluorocarbons OptionB Photochemical oxidents OptionC Sulfur dioxide OptionD Smog

(A) Chlorofluorocarbons

Identify the process through which a country moves from relatively high birth and death rates to relatively low birth and death rates. Select a Choice Below current question choices OptionA Demographic transition OptionB Remediation OptionC Primary population change OptionD Stratospheric depletion

(A) Demographic transition

Choose three factors that primarily account for the reproductive change in Bangladesh. Select a Choice Below current question choices OptionA Desire for children, women's education, and access to mass media OptionB Men's employment status, desire for children, and men's education OptionC Availability of contraceptives, number of children, and population OptionD Communication, women's knowledge, and men's job status

(A) Desire for children, women's education, and access to mass media

Every ecosystem is characterized by which of the following fundamental phenomena? Select a Choice Below current question choices OptionA Energy flow and chemical cycling OptionB Energy and matter OptionC Water and soil OptionD Evaporation and precipitation

(A) Energy flow and chemical cycling

Of the following, which is the best example of a point source of water pollution? Select a Choice Below current question choices OptionA Factory effluent OptionB Storm water OptionC Agricultural runoff OptionD Residential pesticide runoff

(A) Factory effluent

Which of the following is an example of a wetland? Select a Choice Below current question choices OptionA Fens and bogs OptionB Steppes and prairies OptionC Deserts and coral reefs OptionD Chaparrals and grasslands

(A) Fens and bogs

The elements in a column of the Periodic Table: Select a Choice Below current question choices OptionA Have similar properties. OptionB Are in the same period. OptionC Have the same atomic mass. OptionD Have very similar chemical symbols.

(A) Have similar properties.

Which of the following taps the kinetic energy of moving water to generate electricity? Select a Choice Below current question choices OptionA Hydropower OptionB Solar power OptionC Wind power OptionD Nuclear power

(A) Hydropower

An ionic bond is a bond that forms between: Select a Choice Below current question choicesOptionAIons with opposite charge.OptionBAtoms with neutral charge.OptionCOne atom's nucleus and another atom's electronsOptionDThe electrons of two different atoms.

(A) Ions with opposite charge.

Photochemical smog differs from industrial smog in that it: Select a Choice Below current question choices OptionA Is formed in the presence of sunlight. OptionB Has large quantities of soot. OptionC Consists of primary pollutants. OptionD Is an unhealthy mixture of pollutants.

(A) Is formed in the presence of sunlight.

Deep-earth high-density geothermal energy: Select a Choice Below current question choices OptionA Is used to generate electricity. OptionB Is used to heat soil to boost crop production in greenhouses. OptionC Is a form of solar energy. OptionD Has no adverse environmental problems associated with it.

(A) Is used to generate electricity.

When elements form mixtures, the elements: Select a Choice Below current question choices OptionAKeep their original properties OptionBReact to form a new substance with new properties. OptionCCombine in a specific mass ratio. OptionDAlways change their physical state.

(A) Keep their original properties.

Which of the following chemistry discoveries states that "When two or more elements combine to form a compound, their masses in that compound are in a fixed and definite ratio."? Select a Choice Below current question choices OptionALaw of Definite Proportions OptionBLaw of Multiple Proportions OptionCLaw of Conservation of Mass OptionDHess' Law

(A) Law of Definite Proportions

What is most likely to result in low oxygen levels in oceans? Select a Choice Below current question choicesOptionAMassive blooms of microscopic marine plant lifeOptionBPresence of large fishes like the blue whaleOptionCLack of chromium and silicon underwaterOptionDElimination of phytoplankton

(A) Massive blooms of microscopic marine plant life

The competitive exclusion principle is based on experimental evidence but aims to explain an observation about real ecosystems. Which observation is explained by the competitive exclusion principle? OptionA Only one species can occupy a particular niche. OptionB Pioneer plants are not found in an established community. OptionC The diversity of a habitat increases as succession proceeds. OptionD Similar ecosystems develop under similar environmental conditions.

(A) Only one species can occupy a particular niche.

Increasing skin cancer and high mutation rates are the result of: Select a Choice Below current question choices OptionA Ozone depletion OptionB Acid rain OptionC Carbon monoxide pollution OptionD None of the above

(A) Ozone depletion

Plastics are the materials obtained by mixing the __________ with other ingredients which impart special engineering properties. Select a Choice Below current question choices OptionA Resin OptionB Monomer OptionC Catalyst OptionD Any polymer

(A) Resin

What is essential to realize the full benefits of energy efficiency? Select a Choice Below current question choices OptionA Strong policies OptionB Commercial buildings OptionC Lower energy prices OptionD Budgeting methods

(A) Strong policies

Name the process by which one natural community changes into another over a time scale of years to centuries. Select a Choice Below current question choices OptionA Succession OptionB Subduction OptionC Sublimation OptionD Segregation

(A) Succession

Which of the following symbiotic relationships is considered parasitic? Select a Choice Below current question choices OptionA Tapeworm in an intestinal tract of an animal OptionB Bees transporting pollen from flowers OptionC Remora fish swimming under sharks OptionD Birds eating the insects from the back of a hippopotamus

(A) Tapeworm in an intestinal tract of an animal

The order of elements in the Periodic Table is based on: Select a Choice Below current question choicesOptionAThe number of protons in the nucleus.OptionBThe electric charge of the nucleus.OptionCThe number of neutrons in the nucleus.OptionDAtomic mass.

(A) The number of protons in the nucleus.

Identify the term that is collectively used to describe the right-most six columns of the Periodic Table. Select a Choice Below current question choicesOptionAThe p blockOptionBThe d blockOptionCThe s blockOptionDThe f block

(A) The p block

Which statement about the alkali metals is correct? Select a Choice Below current question choicesOptionAThey are located in the left-most column of the Periodic Table.OptionBThey are extremely nonreactive.OptionCThey are usually gases.OptionDThey form negative ions with a 1- charge.

(A) They are located in the left-most column of the Periodic Table.

What are dead zones? Select a Choice Below current question choicesOptionAThey refer to coastal waters that are too low in oxygen to sustain life.OptionBThey refer to areas that are characterized by low annual rainfall.OptionCThey refer to the river waters that are depleted as a result of overuse.OptionDThey refer to regions that are subject to frequent and prolonged droughts.

(A) They refer to coastal waters that are too low in oxygen to sustain life.

Which of the following is a reason for studying environmental science? Select a Choice Below current question choices OptionA To ensure a sustainable future OptionB To study the life on other planets OptionC To understand human behavior in the past OptionD To predict the future technology accurately

(A) To ensure a sustainable future

What refers to the sequential stages in a food chain where organisms that are the same number of steps away from the original energy source are grouped together? Select a Choice Below current question choices OptionA Trophic levels OptionB Marine biomes OptionC Reverse genetics OptionD Cascading layers

(A) Trophic levels

Humans in developed countries would typically have what type of survivorship curve? Select a Choice Below current question choices OptionA Type I OptionB Type II OptionC Type III OptionD Cannot be determined from the given information

(A) Type I

Which factors accounted for the reproductive change in Bangladesh? Select a Choice Below current question choices OptionA Women's educational level OptionB Medical doctor's educational level OptionC Grandparent's educational level OptionD Children's educational level

(A) Women's educational level

The logistic growth curve characterizes a population by: Select a Choice Below current question choices OptionA its total size. OptionB the ratio of young to old individuals. OptionC the ratio of healthy to sick individuals. OptionD the ratio of males to females.

(A) its total size.

The number of electrons in the highest energy level of a neutral calcium (atomic number 20) is: Select a Choice Below current question choices OptionA 2 OptionB 4 OptionC 6 OptionD 8

(A) 2 EXPLANATION Calcium fills the 1s, 2s, 2p, 3s and 3p orbitals completely. There are 2 remaining electrons, which are the valence electrons for calcium.

What is a compound? Select a Choice Below OptionAA substance made up of two or more atoms joined by a chemical reaction OptionBTwo substances not chemically combined OptionCA substance that cannot be separated even by a chemical reaction OptionDTwo substances that can be joined together by physical means

(A) A substance made up of two or more atoms joined by a chemical reaction EXPLANATION A compound is a substance formed when two or more chemical elements are chemically bonded together.

In a human population undergoing the demographic transition, which of the following generally decreases first? Select a Choice Below current question choices OptionA Birth rate OptionB Death rate OptionC Average family size OptionD Life expectancy

(A) Birth rate EXPLANATION In demographic transition, the first stage is characterized by a decrease in the death rate (accompanied by a constant birth rate) to cause the population to slowly increase.

The empirical formula of a substance is CH2O . (Atomic mass for carbon is 12 u, hydrogen 1 u, and oxygen 16 u). Its molar mass is 180. What is the substance's molecular formula?

(A) C8H16O8 EXPLANATION The mass of the empirical formula of the substance is 30 u, where the ratio of carbon : hydrogen : oxygen is 1 : 2 : 1. If you want a molar mass of 180 g, you need six times as many atoms of each kind. So the ratio would then be: 6 : 12 : 6, and the molecular formula would be C6H12O6, or glucose.

Progress through the phases of demographic transition accompanies: Select a Choice Below current question choices OptionA Deterioration of living standards OptionB Economic recession, civil wars and revolutions OptionC Political unrest and civil strife OptionD Increased economic and industrial development

(A) Deterioration of living standards EXPLANATION If the population rises, and the amount of available resources do not, then the living conditions will be lowered as a result.

Which of the following type of chemical reactions results in a single product? Select a Choice Below current question choices OptionADirect combination reaction OptionBDecomposition reaction OptionCSingle replacement reaction OptionDDouble replacement reaction

(A) Direct combination reaction EXPLANATION A synthesis reaction or direct combination reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex product.

When a gas in a cylinder is compressed at constant temperature by a piston, the pressure of the gas increases. Consider the following three statements: I) The rate at which the molecules collide with the piston increases. 2) The average speed of the molecules increases. 3) The molecules collide with each other more often. Which statement(s) correctly explains the increase in pressure? Select a Choice Below current question choicesOptionAI onlyOptionBII onlyOptionCIII onlyOptionDI and III only

(A) I only EXPLANATION When molecules collide with the piston, they exert a force on it which we measure as gas pressure acting against the piston.

Pick the statement that is true of nitrogen. Select a Choice Below current question choices OptionA It is one of the most essential mineral nutrients for all types of ecosystems. OptionB Its absence does not limit the growth of organisms. OptionC It is seldom used as an ingredient in plant fertilizer. OptionD It does not have a gaseous phase like carbon or phosphorus.

(A) It is one of the most essential mineral nutrients for all types of ecosystems. EXPLANATION Nitrogen and phosphorus are two of the most essential mineral nutrients for all types of ecosystems and often limit growth if they are not available in sufficient quantities.

The increase in the size of Earth's human population in the last century has been dramatic. Which of the following identifies two major contributors to this increase? Select a Choice Below current question choices OptionA New methods of agriculture and the identification of new food crops OptionB The Industrial Revolution and modern medicine OptionC Increased emigration/immigration and decreased warfare OptionD New methods of birth control and decreased warfare

(B) The Industrial Revolution and modern medicine

Which of the following makes use of heated water that is deep underground to produce steam to generate electricity? Select a Choice Below current question choices OptionA Wind power OptionB Geothermal power OptionC Nuclear power OptionD Solar power

(B) Geothermal power

Which of the following can be defined as one-twelfth of the mass of a carbon-12 atom? Select a Choice Below current question choices OptionAThe mass number OptionBThe atomic mass unit OptionCThe atomic number OptionDThe isotope number

(B) The atomic mass unit

What triggered the exponential growth rate in humans over the past two hundred years? Select a Choice Below current question choices OptionA Increased death rate and cleaner environments OptionB Greater longevity and healthier lives OptionC Decreased birthrates and eating organic foods OptionD Decreased fertility rate and advanced medical technology

(B) Greater longevity and healthier lives

Hydroelectric power generation from a river is an example of: Select a Choice Below current question choices OptionA Off-stream use OptionB In-stream use OptionC Consumptive use OptionD Geothermal power

(B) In-stream use

Which of the following can cause acid rain? Select a Choice Below current question choices OptionA Soil erosion OptionB Industrial smokestacks OptionC A decrease in the ozone layer OptionD Clear-cutting forests

(B) Industrial smokestacks

Which of the following is a physical change? Select a Choice Below current question choices OptionAEggs rotting OptionBIron turning white when heated OptionCLighter fluid burning OptionDBikes rusting

(B) Iron turning white when heated

What happens to plastic waste? Select a Choice Below current question choices OptionA It is a biodegradable material so eventually it disintegrates. OptionB It never fully goes away; it just breaks into smaller pieces. OptionC There is no such thing as plastic waste; all plastic is recycled. OptionD It is dumped in the ocean for fish to eat.

(B) It never fully goes away; it just breaks into smaller pieces.

Pick the term that refers to a species upon which many other species depend and whose disappearance can trigger impacts throughout an ecosystem. Select a Choice Below current question choices OptionA Invasive species OptionB Keystone species OptionC r-selected species OptionD Endemic species

(B) Keystone species

The presence of which of the following species has inordinate influence in maintaining the prevalence of various species in an ecosystem and the ecological community's structure? Select a Choice Below current question choices OptionA r-selected species OptionB Keystone species OptionC Invasive species OptionD Exotic species

(B) Keystone species

Which of the following chemistry discoveries states that "When two elements combine to form more than one compound, the mass of element A which combines in the first compound with a given amount of element B has a simple whole number ratio with the mass of element A which combines in the second compound with the same given mass of element B."? Select a Choice Below current question choicesOptionALaw of Definite ProportionsOptionBLaw of Multiple ProportionsOptionCLaw of Conservation of MassOptionDHess' Law

(B) Law of Multiple Proportions

Pick the term that refers to the sum of all recurring and non-recurring expenses over the full life span of a good or service. Select a Choice Below current question choices OptionA Total-process expense OptionB Life-cycle cost OptionC Full-cycle charge OptionD Life-time expense

(B) Life-cycle cost

Regions of the ocean are commonly referred to as what type of system? Select a Choice Below current question choicesOptionAMountainousOptionBMarineOptionCEstuaryOptionDDesert

(B) Marine

Identify the term that refers to a very small, specialized habitat within a larger ecosystem. Select a Choice Below current question choices OptionA Alpine habitats OptionB Microhabitats OptionC Monotypic habitats OptionD Marine habitats

(B) Microhabitats

Which mineral nutrient often limits growth when not available in sufficient quantities, and is the most essential for all types of ecosystems? Select a Choice Below current question choices OptionA Boron OptionB Phosphorus OptionC Copper OptionD Chromium

(B) Phosphorus

Which of the following are likely to be present in photochemical smog? Select a Choice Below current question choices OptionA Sulfur dioxide OptionB Photochemical oxidents OptionC Chlorofluorocarbon OptionD Smog

(B) Photochemical oxidents

Through what process do plankton get energy and provide energy to the rest of the ocean? Select a Choice Below current question choicesOptionACarbon cycleOptionBPhotosynthesisOptionCBioerosionOptionDNitrogen cycle

(B) Photosynthesis

One type of competition involves individuals competing for resources. The other involves competition between different: Select a Choice Below current question choices OptionA Organisms OptionB Populations OptionC Environments OptionD Relationships

(B) Populations

Which term describes an animal that eats other animals in the food web? Select a Choice Below current question choices OptionA Prey OptionB Predator OptionC Producer OptionD Primary consumer

(B) Predator

Which of the following statements about urban areas is not true? Select a Choice Below current question choices OptionA There is traffic congestion. OptionB Public utilities are not readily available. OptionC There are higher crime rates. OptionD Slums often develop in and around urban areas.

(B) Public utilities are not readily available.

Which of the following is not a characteristic used to identify a biotic community? Select a Choice Below current question choices OptionA Species diversity OptionB Publicly-owned land versus private property OptionC Trophic structure OptionD Relative species abundance

(B) Publicly-owned land versus private property

What aquatic biome is characterized by flowing fresh water? Select a Choice Below current question choicesOptionALakes/pondsOptionBRivers/streamsOptionCMangrove swampsOptionDCoral reefs

(B) Rivers/streams

Succession that occurs on a site that has been burnt in a forest fire is an example of: Select a Choice Below current question choices OptionA Primary succession OptionB Secondary succession OptionC Tertiary succession OptionD Quarternary succession

(B) Secondary succession

Identify a relatively new form of renewable energy. Select a Choice Below current question choices OptionA Hydropower OptionB Solar power OptionC Nuclear power OptionD Geothermal power

(B) Solar power

The primary cause of acid rain around the world is: Select a Choice Below current question choices OptionA Carbon dioxide OptionB Sulfur dioxide OptionC Carbon monoxide OptionD Ozone

(B) Sulfur dioxide

An ideal gas is a hypothetical gas: Select a Choice Below current question choices OptionA Not made up of particles. OptionB That conforms to all of the assumptions of the Kinetic Theory. OptionC Whose particles have zero mass. OptionD Made of motionless particles.

(B) That conforms to all of the assumptions of the Kinetic Theory.

Name the species that are suited to stable environments that produce a few, relatively large offspring and provide parental care. Select a Choice Below current question choices OptionA Foundation species OptionB K-selected species OptionC T-selected species OptionD Invasive species

(B) K-selected species EXPLANATION K-selected species are suited to stable environments that produce a few, relatively large offspring and provide parental care. They tend to exist close to their carrying capacity.

Pressure is exerted by gases due to their: Select a Choice Below current question choicesOptionACircular motion.OptionBLinear motion.OptionCRandom motion.OptionDVibratory motion.

(B) Linear motion. EXPLANATION Depending on its nature and temperature, the molecules may possess translatory motion, vibratory motion and rotatory motion about its axis. When molecules collide with the container walls, they exert a force on the wall, the sum total of which creates gas pressure.

What is the name of the smallest particle of a substance that is capable of independent existence as that substance? Select a Choice Below current question choicesOptionAAtomOptionBMoleculeOptionCElectronOptionDProton

(B) Molecule EXPLANATION Molecules are a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

The conversion of nitrogen gas to nitrates by bacteria is called: Select a Choice Below current question choices OptionA Nitrification OptionB Nitrogen fixation OptionC Denitrification OptionD Excretion

(B) Nitrogen fixation EXPLANATION By definition, nitrogen fixation is the chemical processes by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle.

The reaction 2KClO3=2KCl+3O2 is an example of what kind of chemical reaction? Select a Choice Below current question choices OptionACombination OptionBDecomposition OptionCCombustion OptionDSynthesis

(B) Decomposition

Choose the term that refers to liquid fuels produced from plant material. Select a Choice Below current question choices OptionA Wood fuels OptionB Geo-fuels OptionC Biofuels OptionD Brown fuels

Which of the following is an example of a physical characteristic property? Select a Choice Below current question choices OptionAColor OptionBHardness OptionCElectrical conductivity OptionDAll of the above

(D) All of the above

Which of the following is a product formed in the chemical reaction that creates the problem of acid rain?

HNO3

Which of the following statements is true? Select a Choice Below Option A In an endothermic process heat is transferred from the surroundings to the system. Option B In an exothermic process heat is transferred from the surroundings to the system. Option C The surroundings will feel cooler in an exothermic process. Option D The surroundings will feel warmer in an endothermic process?

(A) In an endothermic process heat is transferred from the surroundings to the system.

Choose the best way through which the principal-agent problem can be eliminated. Select a Choice Below current question choices OptionA Avoiding habitat destruction OptionB Constructing net zero buildings OptionC Reducing the direct exploitation of plants OptionD Removing the solid waste and sewage created

(B) Constructing net zero buildings

Which of the following substances is released by CFC's and catalyzes a chain reaction that breaks down ozone in the upper atmosphere? Select a Choice Below current question choices OptionA Carbon dioxide OptionB Chlorine OptionC Sulfur dioxide OptionD Methane

(B) Chlorine

When both partners are negatively affected, the nature of the interaction is: Select a Choice Below current question choicesOptionACommensalismOptionBCompetitionOptionCPredationOptionDAmensalism

(B) Competition

If the volume of a confined gas is doubled while the temperature remains constant, what change (if any) would be observed in the pressure? Select a Choice Below current question choices OptionA It would be half as large. OptionB It would double. OptionC It would be four times as large. OptionD It would be ¼ as large.

(A) It would be half as large. EXPLANATION When two variables are inversely proportional, the factor that increases one variable works to decrease the other in a proportional manner. So, if the volume is doubled, the pressure would have to be half as great, so that the product PV remains constant.

Which of the following is not a physical characteristic that is used to identify an element? Select a Choice Below current question choices OptionA Mass OptionB Density OptionC Melting point OptionD Boiling point

(A) Mass EXPLANATION The mass of an object is dependent on how much of it you have, so it isn't a characteristic that can be used to identify a substance.

The term 'meltdown' refers to a nuclear accident in which: Select a Choice Below current question choices OptionA The coolant system fails. OptionB The control rod breaks and radioactive material leaks out. OptionC The reactor vessel explodes. OptionD The concrete containment structure collapses.

(A) The coolant system fails. EXPLANATION A nuclear meltdown is a severe nuclear reactor accident that results in core damage from overheating. It is usually triggered by a failure in the cooling system as a result of malfunctioning equiipment.

In a Type I survivorship curve, the number of survivors remains stable, but eventually decreases sharply at a particular upper age limit. In a Type III survivorship curve, the number of survivors steadily decreases proportionally with an increase in age. Which of the following inferences can be drawn from those descriptions of survivorship curves? Select a Choice Below current question choices OptionA Type I could represent a house mouse, which is typically r-selected. OptionB Type III could be the average of r-selected and k-selected species in a specific area. OptionC Type III could represent elephants, which are typically k-selected species. OptionD Type I could represent an oak tree species that experiences very low survivorship early and late in life.

(A) Type I could represent a house mouse, which is typically r-selected. EXPLANATION Mice are typical of r-selected species which feature the production of numerous small offspring followed by exponential population growth as the defining characteristic. They require short gestation periods, mature quickly (and thus require little or no parental care), and possess short life spans.

Which of the following statements would be true regarding the age structure diagram shown? Select a Choice Below current question choices OptionA A would be typical of a developing country, while B would be typical of a developed country. OptionB A has a population that is declining, while B has a population that is growing. OptionC A would be typical of a country like Japan, while B would be typical of a country like Mexico. OptionD A would be typical of a developed country, while B would be typical of a developing country.

(A)A would be typical of a developing country, while B would be typical of a developed country. EXPLANATION The age structure diagram for A shows lots of young people and not many older people, and that means there will be many babies and a big increase in population. The age structure diagram for B shows a dramatic reduction in the children, which would result from a declining birth rate, and many people grown into adulthood along a normal pattern.

Which of the following is not true about London-type smog? Select a Choice Below current question choices OptionA Its main components are produced by the action of sunlight on emissions of automobiles. OptionB It is produced in cold and humid climates. OptionC It contains compounds of a reducing nature. OptionD It contains smoke, fog, and sulfur dioxide.

(A)Its main components are produced by the action of sunlight on emissions of automobiles. EXPLANATION London-type smog contains reducing agents, but it comes from coal-burning in factories and homes, not from automobiles.

What is urbanization? Select a Choice Below current question choices OptionA The shift from rural to urban living and the increased concentration of the human population in large cities and suburbs OptionB The shift from rural to urban living and the decreased concentration of the human population in densely populated cities OptionC The shift from rural to urban living and the increased concentration of the human population in densely populated areas OptionD The increased concentration of the human population in densely populated cities and rural areas

(A)The shift from rural to urban living and the increased concentration of the human population in large cities and suburbs

Why is the percentage of the world's population that lives in developing countries increasing? Select a Choice Below current question choices OptionA Fertility rates are equal in developing and developed countries. OptionB Fertility rates are higher in developing countries than in developed countries. OptionC Death rates are higher than birth rates in developing countries. OptionD Fertility rates are lower in developing countries.

(B) Fertility rates are higher in developing countries than in developed countries.

What is photochemical smog? Select a Choice Below current question choices OptionA Primary air pollutants produced by burning fossil fuels OptionB Secondary air pollutants produced when chemicals in smog react with sunlight OptionC Primary air pollutants produced when chemicals react with clouds in the troposphere OptionD Secondary air pollutants that are produced by releasing CFC's

(B) Secondary air pollutants produced when chemicals in smog react with sunlight

For a constant temperature, Boyle's Law states that: Select a Choice Below current question choicesOptionAThe pressure of a fixed amount of gas is directly proportional to the volume of the gas.OptionBThe pressure of a fixed amount of gas is inversely proportional to the volume of the gas.OptionCThe pressure of a fixed amount of gas is independent of the volume of the gas.OptionDNone of the above

(B) The pressure of a fixed amount of gas is inversely proportional to the volume of the gas.

What is the molar mass for (NH4)2CO3? (molar masses are 14 g (nitrogen), 1 g (hydrogen), 12 g (carbon) and 16 g (oxygen). Select a Choice Below current question choices OptionA82 g OptionB96 g OptionC120 g OptionD192 g

(B) 96 g

The graph shown could represent the trend for which of the following properties? Graph of sodium, magnesium, aluminum, silicon, phosphorous, sulfur, chlorine and argon. Select a Choice Below current question choices OptionA Ionization energy OptionB Atomic radius OptionC Number of occupied electron shells OptionD Electronegativity

(B) Atomic radius

A slightly underinflated rubber life raft left in bright, summer sunlight swells up. You should not overinflate your life raft when your ship goes down in tropical waters because the average kinetic energy of the gas particles increases and volume of the gas increases. Which law explains this phenomenon? Select a Choice Below current question choices OptionA Boyle's Law OptionB Charles' Law OptionC Gay-Lussac's Law OptionD Ideal Gas Law

(B) Charles' Law EXPLANATION In the bright summer sun, the Kelvin temperature of the gas particles increases; thus, their kinetic energy increases. If the temperature increases, then the volume increases, and the life raft could pop. Charles explains the direct relationship between temperature and volume.

Which of the following sets of elements is in the correct order of increasing atomic radius (smallest to largest)? Select a Choice Below current question choices OptionA P, Si, Al OptionB Cl, Br, I OptionC S, Si, Zn OptionD Se, As, Sb

(B) Cl, Br, I EXPLANATION Atomic radii generally decrease along each period (row) of the table, from the alkali metals to the noble gases; and increase down each group (column). The atomic radii decrease across the Periodic Table because as the atomic number increases, the number of protons increases across the period, but the extra electrons are only added to the same quantum shell. Therefore, the effective nuclear charge towards the outermost electrons increases, drawing the outermost electrons closer. As a result, the electron cloud contracts and the atomic radius decreases.

Pick two of the six factors that primarily account for the reproductive change in Bangladesh. Select a Choice Below current question choices OptionA Men's employment status and poverty OptionB Desire for children and access to mass media OptionC Men's education and employment opportunities OptionD Population size and affluence

(B) Desire for children and access to mass media EXPLANATION Research found that six factors primarily account for the reproductive change in Bangladesh: communication between husbands and wives about family planning, desire for children, women's education, women's employment status, access to mass media, and the effects of family planning program, including availability of contraceptives.

The reaction KCl+AgNO3=KNO3+AgCl is an example of what kind of chemical reaction?

(B) Double replacement EXPLANATION A double replacement reaction is a type of reaction that occurs when the cations and anions switch between two reactants to form new products.

Protons attract electrons. Why do electrons not fall into the nucleus? Select a Choice Below current question choicesOptionANeutrons repel the electrons.OptionBElectrons in ground state cannot radiate energy.OptionCAt very small distances, protons repel electrons.OptionDInner electrons repel those in the outer orbitals.

(B) Electrons in ground state cannot radiate energy. EXPLANATION In a ground state, electrons form standing waves. Standing waves are those in which energy is not transferred. Therefore, electrons are bound to revolve around the nucleus with constant potential energy.

Which of the following is not what chemists investigate? Select a Choice Below current question choices OptionAIdentifying a specific unknown substance OptionBHow likely it is for a newly discovered medicine to become over-the-counter products OptionCHow substances interact, combine and change OptionDUse processes to make new substances

(B) How likely it is for a newly discovered medicine to become over-the-counter products EXPLANATION Chemistry is the study of the interactions of matter with other matter and with energy.

Malthus' theory was that population: Select a Choice Below current question choices OptionA Increased proportionally to economic growth. OptionB Increased geometrically, outstripping food supply, which grew arithmetically OptionC Increased stagnantly with food supply and economic development. OptionD Increased disproportionately, surpassing agricultural production.

(B) Increased geometrically, outstripping food supply, which grew arithmetically EXPLANATION Malthus' basic argument was that increases in agricultural production were linear, while increases in human population were exponential, so the population would eventually outgrow the food source supporting it.

What creates low-oxygen zones in oceans? Select a Choice Below current question choices OptionA Elimination of microscopic marine plant life OptionB Inputs of nitrogen and phosphorous from fertilizer runoff OptionC Lack of phytoplankton OptionD Removing nutrients from coastal waters

(B) Inputs of nitrogen and phosphorous from fertilizer runoff EXPLANATION Inputs of nutrients to coastal waters, mostly nitrogen and phosphorous from fertilizer runoff and untreated wastewater, was leading to massive blooms of microscopic marine plant life known as phytoplankton. When plankton die, they sink to the bottom and are decomposed by other microorganisms in a process that uses up oxygen and creates low-oxygen zones.

If an acid is composed of only one hydrogen and one other element, what would its name look like? Select a Choice Below current question choicesOptionAIt contains "hydrogen-" + the stem of the other element + "-iate acid".OptionBIt contains "hydro-" + the stem of the other element + "-ic acid".OptionCIt contains "hydrogen-" + the stem of the other element + "-ic acid".OptionDIt contains "hydro-" + the stem of the other element + "-ate acid".

(B) It contains "hydro-" + the stem of the other element + "-ic acid". EXPLANATION If an acid is composed of only hydrogen and one other element, the name is "hydro-" + the stem of the other element + "-ic acid"

Which of the following statements about photochemical smog is wrong? Select a Choice Below current question choices OptionA It has a high concentration of oxidizing agents. OptionB It has a low concentration of oxidizing agents. OptionC It can be controlled by the release of NO2, hydrocarbons, ozone, etc. OptionD Planting certain types of vegetation (like oleanders) helps in controlling photochemical smog.

(B) It has a low concentration of oxidizing agents. EXPLANATION Smog has a high concentration of oxidizing agents. The amount of smog can be reduced by technological means, like the catalytic converter installed in automobiles. Certain types of vegetation can be beneficial in addressing the problem of photochemical smog.

Fluorine is a pale yellow gas that reacts with most substances. As a free element, it melts at -220°C and boils at -188°C. Which of the details given is not a physical process? Select a Choice Below current question choices OptionA It is a gas. OptionB It reacts with most substances. OptionC It melts at -220°C. OptionD It boils at -188°C.

(B) It reacts with most substances. EXPLANATION Reacting with something else is always a chemical process.

Which of the following is not a postulate on which the Atomic Molecular Theory was developed? Select a Choice Below current question choicesOptionACompounds consist of identical molecules formed of atoms combined in simple whole number ratios.OptionBIf equal amounts of reactant are used, then equal amounts of product are formed.OptionCThe elements are comprised of identical atoms.OptionDAll atoms of a single element have the same characteristic mass.

(B)If equal amounts of reactant are used, then equal amounts of product are formed. EXPLANATION The postulates on which the Atomic Molecular Theory was developed include: 1) The elements are comprised of identical atoms; 2) All atoms of a single element have the same characteristic mass; 3) These number and masses of these atoms do not change during a chemical transformation; and 4) Compounds consist of identical molecules formed by atoms combined in simple whole number ratios.

Which of the following statements about symbiotic relationships is true? Select a Choice Below current question choicesOptionAIn a parasitic relationship, both organisms are harmed.OptionBSymbiotic organisms have undergone little or no co-evolution.OptionCA relationship that appears to be commensalistic may in fact be mutualistic or parasitic.OptionDThe most efficient type of parasite is one that kills its host.

What is the ozone layer? Select a Choice Below current question choices OptionA It is the area of the stratosphere where problems like smog and acid rain originate. OptionB It is a region of the upper atmosphere where ozone is being deposited by pollution from modern society. OptionC It is a region of the upper atmosphere that normally shields humans from excessive ultra-violet radiation. OptionD It is the name of the antiballistic defense shield placed in eastern Europe.

An element such as neon can sometimes give off light because: Select a Choice Below current question choices OptionA Its electrons gain energy and give off light as they move to a higher energy level. OptionB It is radioactive. OptionC Its electrons gain energy and give off light as they fall back to a lower level. OptionD Its atoms all have positive charge.

Which of the following statements about orbitals is incorrect? Select a Choice Below current question choices OptionA Orbitals can hold up to two electrons. OptionB Orbitals are regions in space where one is likely to find an electron. OptionC Orbitals can hold two electrons, provided they are spinning in the same direction. OptionD s, p, d, and f orbitals are possible.

Which of the following is the best definition of chemistry as a scientific endeavor? Select a Choice Below current question choicesOptionAStudy and practice of making basic materials and determining their characterOptionBStudy of the complex emotional or psychological interaction between two peopleOptionCStudy of substances, their properties and structure, and the changes they undergoOptionDStudy of the interaction of matter with other matter and with energy

Based on Malthus' ideas, which of the following is a true statement? Select a Choice Below current question choices OptionA Supply of food grain increases in geometric proportion (exponentially) while world population increases in arithmetic proportion (linearly). OptionB Supply of food grain increases in arithmetic proportion (linearly) while world population increases in arithmetic proportion (linearly). OptionC Supply of food grain increases in arithmetic proportion (linearly) while world population increases in geometric proportion (exponentially). OptionD Supply of food grain increases in geometric proportion (exponentially) while world population increases in geometric proportion (exponentially).

(C) Supply of food grain increases in arithmetic proportion (linearly) while world population increases in geometric proportion (exponentially).

What is the relationship between first ionization energy and the reactivity of a metal? Select a Choice Below current question choices OptionA The reactivity of a metal is not related to its first ionization energy. OptionB The higher the first ionization energy, the higher the reactivity of the metal. OptionC The lower the first ionization energy, the higher the reactivity of the metal. OptionD The lower the first ionization energy, the lower the reactivity of the metal.

Which statement is NOT true of the Gulf of Mexico oil spill of 2010? Select a Choice Below current question choices OptionA Detecting a link between mortality and the oil spill is not always so clear-cut. OptionB Some of the worst predictions made by scientists, after the spill, have not materialized. OptionC The number of aquatic animals killed as a result of the spill was easily estimated. OptionD It could be years or even decades before the full effects of the Gulf spill are understood.

How many moles are in 88 g of CO2? The molar masses are 12 g (carbon) and 16 g (oxygen). Select a Choice Below current question choicesOptionA0.5 moleOptionB1.0 moleOptionC2.0 moleOptionD4.0 mole

Which major ecological community type is characterized by a similar climate, soil, plants, and animals? Select a Choice Below current question choicesOptionAA preserveOptionBA zoneOptionCA biomeOptionDA channel

An atom of sodium has an atomic number of 11 and a mass number of 23. Which of the following statements is correct? Select a Choice Below current question choices OptionAAn atom of sodium has 11 protons, 11 electrons, and 11 neutrons. OptionBAn atom of sodium has 11 protons, 12 electrons, and 11 neutrons. OptionCAn atom of sodium has 11 protons, 11 electrons, and 12 neutrons. OptionDAn atom of sodium has 11 protons, 12 electrons, and 12 neutrons.

What term refers to highways that encircle an urban area? Select a Choice Below current question choices OptionA Tailings OptionB Aquifers OptionC Beltways OptionD Landways

What refers to the buildup of a substance, such as a toxin, in an organism's body? Select a Choice Below current question choices OptionA Incineration OptionB Perturbation OptionC Bioaccumulation OptionD Toxification

Carbon is recycled through food chains and the inorganic parts of the carbon cycle. However, energy flows in only one direction through a food chain and is not recycled. This is because: Select a Choice Below current question choices OptionA Cellular processes convert chemical energy into new matter. OptionB Decomposers transfer energy to space before it can be reused. OptionC Chemical energy is converted to heat at each step in a food chain. OptionD Chemical energy cannot be converted into any other form of energy.

If scientists are studying the egrets, herons, marsh crabs, and cordgrass, but not the water or rocks in a salt marsh, what level of organization would they be studying? Select a Choice Below current question choicesOptionAIndividual organismOptionBPopulationOptionCCommunityOptionDEcosystem

What is a consequence of the Gulf of Mexico oil spill of 2010? Select a Choice Below current question choices OptionA Increased levels of oxygen underwater OptionB Massive blooms of phytoplankton OptionC Death of birds and sea mammals OptionD Accumulation of nutrients at coastal waters

The conversion of nitrates to nitrogen gas by bacteria is called: Select a Choice Below current question choices OptionA Nitrification OptionB Nitrogen fixation OptionC Denitrification OptionD Excretion

When we study a(n) __________, we are concerned with the community plus its physical and chemical environment. Select a Choice Below current question choices OptionA Habitat OptionB Niche OptionC Ecosystem OptionD Population

Which of the following is NOT a possible cause of mass extinction? Select a Choice Below current question choices OptionA Volcanic eruptions OptionB Meteorites colliding with the earth OptionC Evapotranspiration OptionD Changing climate

The addition of heat causes particles to ____________ their motion. Select a Choice Below current question choices OptionA Counteract OptionB Decrease OptionC Increase OptionD Stay the same

One way to increase pressure on a gas is to: Select a Choice Below current question choices OptionA Decrease temperature. OptionB Increase volume. OptionC Increase the number of gas particles. OptionD Lower the kinetic energy of the gas molecules.

What is the rule for naming a binary acid? Select a Choice Below current question choices OptionA It contains "hydro-" + the stem of the other element + "-ate acid". OptionB It contains "hydrogen-" + the stem of the other element + "-iate acid". OptionC It contains "hydro-" + the stem of the other element + "-ic acid". OptionD It contains "hydrogen-" + the stem of the other element + "-ic acid".

Identify the biomes that are typically named for their characteristic types of vegetation, which in turn influence what kinds of animals will live there. Select a Choice Below current question choices OptionA Marine biomes OptionB Freshwater biomes OptionC Land biomes OptionD Aquatic biomes

Which of the following is not a practical partial solution to the problem of photochemical smog? Select a Choice Below current question choices OptionA Decreasing our use of conventional motor vehicles OptionB Using catalytic converters on our motor vehicles OptionC Making artificial rain to wash the polluting gases from the air in cities OptionD Obtaining more electricity from renewable sources such as wind turbines

What term is used to refer to urban regions of more than 10 million people? Select a Choice Below current question choices OptionA Suburbs OptionB Aquifers OptionC Megacities OptionD Semi-arid regions

As you move down the same column of the Periodic Table, elements have: Select a Choice Below current question choices OptionA Fewer protons. OptionB A lower atomic number. OptionC More energy levels. OptionD A different group number.

Pick an example of a fossil fuel.

Which of the following statements is not a part of the Kinetic-Molecular theory of gases? Select a Choice Below current question choices OptionA Matter is composed of particles that are in constant motion. OptionB Particle velocity increases as the temperature increases. OptionC Particles in a system cannot transfer energy to each other. OptionD Particle interactions involve electrostatic attractions and repulsions.

Which of the following factors is least likely to influence human fertility? Select a Choice Below current question choices OptionA Level of affluence OptionB Average marriage age OptionC Personality characteristics OptionD Availability of birth control

Reasons for preserving biodiversity include all of the following except: Select a Choice Below current question choices OptionA Isolating unique genetic material so it can be incorporated into existing crops OptionB Increasing the chances of discovering organisms with medicinal value OptionC Preventing natural evolution OptionD Finding new plants that can supplement the world's food supply

In order to keep costs low, Core Inc. office builders cut corners on energy efficient features during construction of offices. However, the people who pay the energy bills are those who occupy those offices. Which of the following is exemplified in the scenario? Select a Choice Below current question choicesOptionAFischer-Tropsch processOptionBSource-receptor relationshipOptionCPrincipal-agent problemOptionDUtilitarian conservation

Pick the term that refers to the sources of oil, natural gas, or coal that have been discovered and determined to be recoverable, but have not yet produced. Select a Choice Below current question choices OptionA Mineral deposits OptionB Methane hydrates OptionC Proved reserves OptionD Secure landfills

Which of the following is/are natural contributors to sulfur dioxide in the atmosphere? Select a Choice Below current question choices OptionA Sea sprays OptionB Decaying vegetation OptionC Volcanic erupcion OptionD All of the above

(D) All of the above

How was Bohr able to discover the energies of each energy level in the hydrogen atom? Select a Choice Below current question choicesOptionAHe used the fact that most alpha particles went straight through the gold foil.OptionBHe used the fact that some alpha particles were deflected by the gold foil.OptionCHe used the line spectrum of hydrogen when it is excited.OptionDHe used the fact that atoms are electrically neutral.

(C) He used the line spectrum of hydrogen when it is excited. EXPLANATION The line spectrum allowed Bohr to convert the wavelength to energy, and that energy was released as photons of light as the atom slipped back into an unexcited state.

Which two variables are thought to be held constant in Charles' Law? Select a Choice Below current question choices OptionA Volume and number of gas particles OptionB Temperature and number of gas particles OptionC Pressure and number of gas particles OptionD Number of gas particles only

(C) Pressure and number of gas particles EXPLANATION Charles' Law relates volume and temperature, while assuming that pressure and the number of gas particles remains the same.

The reaction Mg(s)+2HCl(aq)=H2(g)+MgCl2(aq) is an example of what kind of chemical reaction? Select a Choice Below current question choices OptionACombination OptionBDecomposition OptionCSingle replacement OptionDDouble replacement

(C) Single replacement EXPLANATION A single-displacement reaction, also known as a single-replacement reaction, is a type of chemical reaction where an element reacts with a compound and takes the place of another element in that compound.

One simple example of an oxidation reaction involves a: Select a Choice Below current question choices OptionASingle replacement reaction where oxygen is removed from a compound OptionBDecomposition reaction of a compound containing oxygen OptionCSingle replacement reaction where oxygen displaces another element OptionDA reaction of a substance with oxygen

(C) Single replacement reaction where oxygen displaces another element EXPLANATION While oxidation now involves the transfer of electrons, its historical origins were in forming oxides of metals, which is a single replacement reaction with oxygen displacing another element.

(C) Slow population growth EXPLANATION In the theory of demographic transition, Phase 1 features a stable growth rate and a slowly decreasing death rate, which combines to produce a slow population growth.

The exchange pool in the carbon cycle is: Select a Choice Below current question choices OptionA Fossil fuels OptionB Sedimentary rock OptionC The oceans OptionD The atmosphere

(C) The oceans EXPLANATION The ocean contains the largest active pool of carbon near the surface of the Earth.[2] The natural flows of carbon between the atmosphere, ocean, terrestrial ecosystems, and sediments are fairly balanced so that carbon levels would be roughly stable without human influence.[4][5]

In the process of succession, which of the following is true of K-selected plant species? Select a Choice Below current question choices OptionA They usually reproduce early in life. OptionB They are usually found in climax stages of succession. OptionC They are the dominant species in early stages of succession. OptionD They have a short lifespan.

(C) They are the dominant species in early stages of succession. EXPLANATION Because K-selected organisms prefer stable environments, they usually show up in the latter stages of succession, also called the climax stages.

The nuclear fuel cycle includes all of the following except: Select a Choice Below current question choices OptionA The mining of uranium ore OptionB The processing of uranium fuel rods OptionC Transportation of uranium to a power plant OptionD Disposal of radioactive waste

(C) Transportation of uranium to a power plant EXPLANATION The nuclear fuel cycle represents the progression of nuclear fuel from creation to disposal. It includes mining, processing, reprocessing of spent fuel, and disposal of radioactive waste. It does not include transporation of fuel rods to power plants.

The name dinitrogen tetraoxide tells you that this compound contains: Select a Choice Below current question choicesOptionATwo nitrogen atoms and two oxygen atomsOptionBFour nitrogen atoms and two oxygen atomsOptionCTwo nitrogen atoms and four oxygen atomsOptionDFour nitrogen atoms and four oxygen atoms

(C) Two nitrogen atoms and four oxygen atoms EXPLANATION 'Di' means that there are two nitrogen atoms, and 'tetra' means there are four oxygen atoms.

Which of the following is not a postulate on which the Atomic Molecular Theory was developed? Select a Choice Below current question choices OptionAThe elements are comprised of identical atoms. OptionBAll atoms of a single element have the same characteristic mass. OptionCUnder certain conditions, it is possible to change one element into another. OptionDThe numbers and masses of atoms do not change during a chemical transformation.

(C) Under certain conditions, it is possible to change one element into another. EXPLANATION The postulates on which the Atomic Molecular Theory was developed include: 1) The elements are comprised of identical atoms; 2) All atoms of a single element have the same characteristic mass; 3) These number and masses of these atoms do not change during a chemical transformation; and 4) Compounds consist of identical molecules formed by atoms combined in simple whole number ratios.

A temperature inversion occurs when: Select a Choice Below current question choices OptionA Cold air lies on top of warm air near the stratosphere. OptionB Warm air lies on top of cold air near the stratosphere. OptionC Warm air lies on top of cooler air near the ground. OptionD Cold air lies on top of warm air next to the ground.

(C) Warm air lies on top of cooler air near the ground. EXPLANATION Temperature inversion, a reversal of the normal behaviour of temperature in the troposphere (the region of the atmosphere nearest the Earth's surface), in which a layer of cool air at the surface is overlain by a layer of warmer air. (Under normal conditions air temperature usually decreases with height.)

Name the compound Zn3(PO4)2. Select a Choice Below current question choicesOptionAZinc potassium oxideOptionBTrizinc PolyoxideOptionCZinc phosphateOptionD Zinc phosphite

(C) Zinc phosphate EXPLANATION The molecular formula shows ionic charges of +2 and -1 being balanced, but they involve the zinc and phosphate ions.

Gause's principle of competitive exclusion is, essentially: Select a Choice Below current question choicesOptionAThe more abundant species will exclude the less abundant species through competition.OptionBCompetition for the same resources excludes species having different life styles.OptionCNo two species can occupy the same niche indefinitely when resources are limited.OptionDLarger organisms exclude smaller ones through competition as in the case of large trees controlling underbrush.

(C)No two species can occupy the same niche indefinitely when resources are limited. EXPLANATION The competitive exclusion principle states that two species that compete for the exact same resources cannot stably coexist. One of the two competitors will always have an ever so slight advantage over the other that leads to extinction of the second competitor in the long run or to an evolutionary shift of the inferior competitor towards a different ecological niche. As a consequence, competing related species often evolve distinguishing characteristics in areas where they both coexist.

Which of the following statements is not consistent with the Kinetic-Molecular theory of gases? Select a Choice Below current question choices OptionA Individual gas molecules are relatively far apart. OptionB The actual volume of the gas molecules themselves is very small compared to the volume occupied by the gas at ordinary temperatures and pressure. OptionC The average kinetic energies of different gases are different at the same temperature. OptionD There is no net gain or loss of the total kinetic (translational) energy in collisions between gas molecules.

(C)The average kinetic energies of different gases are different at the same temperature. EXPLANATION Since temperature is the measure of average kinetic energy, gases at the same temperature should have the same average kinetic energy.

Which is true of unconventional deposits? Select a Choice Below current question choices OptionA The amounts of oil and gas contained in unconventional deposits tend to be very small. OptionB It historically has provided most of the oil and gas produced. OptionC Recovering unconventional deposits is relatively easy and inexpensive. OptionD An example of an unconventional natural gas deposit is coalbed methane.

(D) An example of an unconventional natural gas deposit is coalbed methane.

What is true of nuclear power? Select a Choice Below current question choices OptionA Few nuclear reactors are based on the concept of nuclear fission. OptionB To generate electricity, it uses heated water that is deep underground. OptionC Nuclear resources can directly provide hot water for industrial purposes. OptionD Concerns over nuclear safety have hindered the development of this energy source.

(D) Concerns over nuclear safety have hindered the development of this energy source.

A food web is more realistic than a food chain for showing the feeding relationships in ecosystems because: Select a Choice Below current question choices OptionA It compares the number of consumers to the number of micro-organisms in an ecosystem. OptionB Food chains use only a small sampling of organisms. OptionC A food web explains why there are more producers than consumers. OptionD Producers are usually eaten by many different consumers and most consumers are eaten by more than one predator.

(D) Producers are usually eaten by many different consumers and most consumers are eaten by more than one predator.

Complete the following sentence: "Different isotopes of the same element have...." Select a Choice Below current question choicesOptionAThe same number of protons, but different numbers of neutrons and electronsOptionBThe same number of neutrons, but different numbers of protons and electronsOptionCThe same number of protons and neutrons, but different numbers of electronsOptionDThe same number of protons and electrons, but different numbers of neutrons

(D) The same number of protons and electrons, but different numbers of neutrons

The removal of tropical forests is related to all of the following global concerns except: Select a Choice Below current question choices OptionA Their role in maintaining the oxygen and carbon balance of the earth. OptionB Their ability to regulate surface and air temperatures, moisture content and reflectivity. OptionC Their contribution to the biological diversity of the planet. OptionD Their ability to absorb the chemicals that contribute to depletion of the ozone layer.

(D) Their ability to absorb the chemicals that contribute to depletion of the ozone layer.

In more general terms, what is a substance that is (1) made of a single element like gold (Au) or a compound of elements like salt (NaCl) and (or) (2) a building block of rock? Select a Choice Below current question choices OptionA A spicule OptionB A follicle OptionC An enzyme OptionD A mineral

(D) A mineral

Effects of acid rain include which of the following? Select a Choice Below current question choices OptionA Deterioration of monuments OptionB Damage to vegetation OptionC Damage to lakes and their wildlife OptionD All of the above

(D) All of the above

Humans are exposed to radiation when they ingest: Select a Choice Below current question choices OptionA Fish OptionB Vegetables OptionC Milk OptionD All of the above

(D) All of the above

The Bohr Model of the atom says that electrons: Select a Choice Below current question choices OptionA Electrons exist at different energy levels in orbit around the nucleus. OptionB Electrons can move between energy levels when they gain or lose energy. OptionC Move at a very high velocity around the nucleus. OptionD All of the above

(D) All of the above

What is acid rain? Select a Choice Below current question choices OptionA Rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes OptionB Rain polluted by acid that has been released into the atmosphere from factories and other industrial processes OptionC Rain or any other form of precipitation that is unusually acidic OptionD All of the above

(D) All of the above

What is the disadvantage to using wind power to generate electricity? Select a Choice Below current question choices OptionA Wind direction is highly variable. OptionB Wind velocity is highly variable. OptionC Wind duration is highly variable. OptionD All of the above

(D) All of the above

Which of the following is a 'down side' of replacing an old, diverse ecosystem with one that is man-made and less diverse? Select a Choice Below current question choices OptionA Man-made ecosystems require care. OptionB Man-made ecosystems require money. OptionC Man-made ecosystems are often less diverse than those naturally occurring. OptionD All of the above

(D) All of the above

How is chemistry different from biology? Select a Choice Below current question choices OptionAChemistry as 'right answers'; biology has 'investigations' OptionBYou can see biological organisms; you cannot see chemical molecules OptionCBiological interactions can involve reproduction; chemical interactions only involve regrouping the atoms involved in the reactions in some formal way. OptionDBiology restricts its attention to living things, while chemistry focuses on interactions taking place between chemical elements (non-living).

(D) Biology restricts its attention to living things, while chemistry focuses on interactions taking place between chemical elements (non-living).

The reaction Fe+S=FeS is an example of what kind of chemical reaction? Select a Choice Below current question choices OptionADouble replacement OptionBSingle replacement OptionCDecomposition OptionDCombination

(D) Combination

Which of the following is not a major characteristic feature of biodiversity hot spots? Select a Choice Below current question choices OptionA Large number of species OptionB Abundance of endemic species OptionC Large number of exotic species OptionD Destruction of habitat

(D) Destruction of habitat

The reaction BaCl2+Na2SO4=BaSO4+2NaCl is an example of what kind of chemical reaction? Select a Choice Below current question choices OptionACombination OptionBDecomposition OptionCSingle replacement OptionDDouble replacement

(D) Double replacement

Which of the following can be defined as achieving the same outcome, such as driving a mile, while using less energy? Select a Choice Below current question choices OptionA Energy conservation OptionB Energy dissipation OptionC Energy sufficiency OptionD Energy efficiency

(D) Energy efficiency

What do we call the regions of the marine biome where rivers and streams flow into the oceans? Select a Choice Below current question choicesOptionACoral reefsOptionBEuphotic zonesOptionCTrenchesOptionDEstuaries

(D) Estuaries

Which of the following groups of species is experiencing a decline in global diversity? Select a Choice Below current question choices OptionA Fish/amphibians only OptionB Fish/amphibians and birds/reptiles OptionC Fish/amphibians and mammals OptionD Fish/amphibians, birds/reptiles and mammals

(D) Fish/amphibians, birds/reptiles and mammals

A fossil fuel is best described as a: Select a Choice Below current question choices OptionA Flammable solid or gas. OptionB A fuel that contains carbon. OptionC Fossilized rock that will burn in a power station OptionD Flammable substance formed from ancient biological material`

(D) Flammable substance formed from ancient biological material

Which watery biome has the lowest concentration of salt? Select a Choice Below current question choicesOptionAOceanOptionBWetlandsOptionCCoral reefOptionDFresh water

(D) Fresh water

A parasite may be described as an organism that derives nourishment from another living organism and: Select a Choice Below current question choices OptionA Becomes necessary to the life of the host OptionB Is neutral in its effect on the host OptionC Benefits the host nutritionally OptionD Harms the host in the process

(D) Harms the host in the process

Which combination of factors will produce the highest rate of population growth? Select a Choice Below current question choices OptionA High life expectancy and high infant mortality OptionB Low life expectancy and low infant mortality OptionC Low life expectancy and high infant mortality OptionD High life expectancy and low infant mortality

(D) High life expectancy and low infant mortality

Which of the following is most likely to result from destruction of wetlands surrounding a river? Select a Choice Below current question choices OptionA Decreased sediment load in the river OptionB Decreased levels of pollutants like nitrates in the river OptionC Increase in diversity of aquatic species in the river OptionD Increase in the frequency of flooding in the river valley

(D) Increase in the frequency of flooding in the river valley

Fighting over shared resources is called: Select a Choice Below current question choices OptionA Competitive exclusion OptionB Predation OptionC Exploitative competition OptionD Interference competition

(D) Interference competition

In a marine biome, organisms experience radical changes in their environment each day in the: Select a Choice Below current question choicesOptionADeep-sea zone.OptionBOpen-sea zoneOptionCNeritic zone.OptionDIntertidal zone.

(D) Intertidal zone.

Which of the following is not a trend that varies systematically in the periodic table? Select a Choice Below current question choices OptionA Electronegativity OptionB Ionization energy OptionC Atomic radius OptionD Ionic radius

(D) Ionic radius

If the absolute temperature of a gas is doubled and the pressure of the gas is halved, how will the volume change? Select a Choice Below current question choicesOptionAIt will increase to two times its original value.OptionBIt will decrease to one-fourth its original value.OptionCIt will stay the same as its original value.OptionDIt will increase to four times its original value.

(D) It will increase to four times its original value.

Pick the term that refers to species that are adapted to stable, predictable environments, and tend to exist close to their carrying capacity. Select a Choice Below current question choices OptionA Exotic species OptionB Endemic species OptionC S-selected species OptionD K-selected species

(D) K-selected species

Which of the following factors do not contribute to the overall growth rate of a population? Select a Choice Below current question choices OptionA Birth rates OptionB Death rates OptionC Fertility rates OptionD Migration rates

(D) Migration rates

An example of a producer is a: Select a Choice Below current question choices OptionA Fungus OptionB Caterpillar OptionC Bird OptionD Moss

(D) Moss

Only a small amount of the energy stored in food is available to the next organism in the food chain because: Select a Choice Below current question choices OptionA There are more producers than consumers in a food chain. OptionB There are fewer top consumers than producers in a food chain. OptionC Primary and secondary consumers compete for food. OptionD Most of the energy is used for life processes.

(D) Most of the energy is used for life processes.

Which of the following is the best definition of a mole? Select a Choice Below current question choices OptionAA mole is 12 grams of any element. OptionBA mole of any substance contains the same number of particles as 12 g of naturally occurring carbon. OptionCA mole is 6.02x10>23 atoms of any substance. OptionDA mole of any substance contains the same number of particles as 12 g of 12C.

(D) A mole of any substance contains the same number of particles as 12 g of 12C. EXPLANATION By definition, 1 atomic mass unit is a unit of mass used to express atomic and molecular weights, equal to one-twelfth of the mass of an atom of carbon-12.

What causes low levels of oxygen in oceans? Select a Choice Below current question choicesOptionAFish and other marine organisms fleeing large areas of oceanOptionBDecreasing microscopic marine plant lifeOptionCLack of sulfur and zinc underwaterOptionDAdding nutrients to coastal waters

(D) Adding nutrients to coastal waters EXPLANATION Inputs of nutrients to coastal waters, mostly nitrogen and phosphorous from fertilizer runoff and untreated wastewater, was leading to massive blooms of microscopic marine plant life known as phytoplankton. When plankton die, they sink to the bottom and are decomposed by other microorganisms in a process that uses up oxygen and creates low-oxygen zones.

As the population of current developing countries undergo a demographic transition, which of the following are most likely to occur? Select a Choice Below current question choices OptionA Urban populations will increase as people migrate to the cities to find employment. OptionB Rural populations will increase as larger populations will require more food. OptionC Food shortages and famines will decrease as an increase in urban populations increases the efficiency of food distribution and supply. OptionD All of the above

(D) All of the above EXPLANATION As the population increases, more people will move to cities for employment. Also, more people will be actively involved in agriculture and other necessary societal functions. Finally, food distribution becomes more efficient as the population concentrates in urban areas.

From the following, identify the simplest type of chemical substance. Select a Choice Below current question choices OptionAA compound OptionBA heterogeneous mixture OptionCA homogeneous mixture OptionDAn element

(D) An element EXPLANATION An element is the simplest type of chemical substance; it cannot be broken down into simpler chemical substances by ordinary chemical means.

What is the theory based on these three ideas: 1) All matter is composed of atoms; 2) Atoms of the same element are the same; atoms of different elements are different; and 3) Atoms combine in whole-number ratios to form compounds? Select a Choice Below current question choices OptionANuclear Theory OptionBAvogadro Theory OptionCNomenclature Theory OptionDAtomic Theory

(D) Atomic Theory EXPLANATION The concept that atoms play a fundamental role in chemistry is formalized by the modern atomic theory, first states by John Dalton, an English scientist, in 180s and consists of 3 parts: 1. All matter is composed of atoms. ; 2) Atoms of the same element are the same; atoms of different elements are different; 3. Atoms combine in whole-number ratios to form compounds.

Which of the following is a chemical change? Select a Choice Below current question choices OptionA Boiling water OptionB Crushing an aspirin tablet OptionC Evaporation of water off of a lake OptionD Burning firewood

(D) Burning firewood EXPLANATION Burning something involves a type of chemical reaction called oxidation.

Elements in an element family have similar: Select a Choice Below current question choicesOptionAAtomic symbolsOptionBAtomic sizesOptionCAtomic weightsOptionDChemical properties

(D) Chemical properties EXPLANATION The grouping of elemental families within columns comes from those members having the same number of valence electrons, which determines most of the chemical properties a substance has.

A green color is obtained in the flame test for a barium salt. The energy producing this color is emitted when: Select a Choice Below current question choicesOptionAElectrons in the highest orbital levels are expelled.OptionBOxidation takes place.OptionCElectrons are raised to higher energy levels by the heat of the flame.OptionDElectrons drop back to lower energy levels.

(D) Electrons drop back to lower energy levels. EXPLANATION The way an atom is able to drop back to a ground energy state is by releasing photons of light, whose energy matches the amount of energy the atom needs to lose.

Pick the two categories of accessible runoff available to meet human water needs. Select a Choice Below current question choices OptionA Seawater that is desalinated and base river flow OptionB Nonrenewable seawater and captured floodwater OptionC In-place water resources and nonrenewable ground water OptionD Floodwater stored in reservoirs and renewable ground water

(D) Floodwater stored in reservoirs and renewable ground water EXPLANATION There are two categories of accessible runoff available to meet human water needs: (1) renewable ground water and base river flow, and (2) floodwater that is captured and stored in reservoirs.

What is not true about a mole? Select a Choice Below current question choicesOptionAIt is a very large number of things.OptionBIts numerical value is often called Avogadro's number.OptionCA mole of a substance has the same mass in grams as one atom has in atomic mass units.OptionDIt is a combination of atoms forming a specific type of molecule.

(D) It is a combination of atoms forming a specific type of molecule.

What is a material made up of two or more substances that can be separated by physical means? Select a Choice Below current question choices OptionAMolecule OptionBElement OptionCCompound OptionDMixture

(D) Mixture EXPLANATION A mixture contains two or more substances that are not chemically combined.

Which of the following statements regarding photochemical smog is not correct? Select a Choice Below current question choices OptionA Carbon monoxide does not play any role in photochemical smog formation. OptionB Photochemical smog is an oxidizing agent in character. OptionC Photochemical smog is formed through photochemical reactions involving solar energy. OptionD Photochemical smog does not cause irritation in eyes and throat.

(D) Photochemical smog does not cause irritation in eyes and throat. EXPLANATION Photochemical smog is formed in warm and sunny climates during day time by the action of sunlight on primary pollutants. It contains nitrogen oxides, ozone, PAN, etc., which are oxidizing in nature, so photochemical smog is an oxidizing agent in character. It causes irritation of the nose and throat.

What is the definition of chemistry as a scientific endeavor? Select a Choice Below current question choices OptionAStudy of the interaction of matter with energy OptionBStudy and practice of making basic materials OptionCStudy of the emotional or psychological interactions between people OptionDStudy of substances, their properties and interactions

(D) Study of substances, their properties and interactions EXPLANATION Webster defines chemistry as "a science that deals with the structure and properties of substances and with the changes that they go through."

Which of the following gases are main contributors to acid rain? Select a Choice Below current question choices OptionA Carbon dioxide and carbon monoxide OptionB Sulfur dioxide and carbon dioxide OptionC Sulfur dioxide and nitrogen dioxide OptionD Sulfur dioxide and nitric oxide

(D) Sulfur dioxide and nitric oxide EXPLANATION Sulfur dioxide and nitric oxide have a high tendency to mix with water to form sulfurous/sulfuric acid and nitric acid.

Consider the balanced equation N2+3H2=2NH3. How many grams of H2 are required to produce 68.0 g of NH3? Select a Choice Below current question choicesOptionA6.0 gOptionB12.0 gOptionC24.0 gOptionD68.0 g

B) 12.0 g

The largest desert in the world is in: Select a Choice Below current question choicesOptionAAustraliaOptionBAfricaOptionCSouth AmericaOptionDNorth America

B) Africa

What is the name used to describe a substance for which all the atoms in it are alike? Select a Choice Below current question choices OptionAMixture OptionBElement OptionCCompound OptionDSolution

B) Element

Which of the following is true of the Jordan River? Select a Choice Below current question choices OptionA The waters of the Jordan are exclusively used by the Jordan Territory. OptionB It is located in the Middle East which faces significant water challenges. OptionC Unlike the Colorado River, the Jordan River can reach the sea. OptionD It is wedged between four nations, namely, Nigeria, Niger, Chad, and Cameroon.

B) It is located in the Middle East which faces significant water challenges.

Pick the underlying reason for the depletion of great rivers such as the Yellow in China. Select a Choice Below current question choices OptionA Viewing rivers as suppliers of vital ecosystem services to plants and animals OptionB Viewing rivers as merely tools for human and economic development OptionC Overusing rivers in the process of fish farming OptionD Using rivers mostly for municipal purposes such as for drinking and cleaning

B) Viewing rivers as merely tools for human and economic development

A "region of space in which there is a high probability of finding an electron" is the definition of: Select a Choice Below current question choices OptionA Orbital OptionB Quantum OptionC Photon OptionD Dipole

OptionA Orbital

Which of the following is not an empirical formula? Select a Choice Below current question choices OptionA Al3(SO4)2 OptionB N2O4 OptionC Na2SO4 OptionD C3H8

OptionB N2O4

As a combustion reaction, what would be the products formed by this reaction CH4+2O2? Select a Choice Below current question choices OptionA CH2+2H20 OptionB C2O+H2O OptionC CO2+2H20 OptionD CO2+H2

OptionC CO2+2H20

What is the empirical formula for a compound that is 36.1% Ca and 63.9% Cl? (atomic masses are 40 u for calcium and 35.5 for chlorine) Select a Choice Below current question choices OptionA CaCl OptionB Ca2Cl OptionC CaCl2 OptionD Ca2Cl2

OptionC CaCl2

Which of the following is a type of biofuel? Select a Choice Below current question choices OptionA Firewood OptionB Ethanol produced by algae OptionC Ethanol produced by bacteria OptionD All of the above

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