Physical Science Midterm 1
How is 0.00069 written in scientific notation? 69 X 10^-5 6.9 X 10^4 0.69 X 10^-3 6.9 X 10^-4
6.9 X 10^-4
Distilled water has a hydronium ion concentration of 1 x 10^-7 M. What is the pH of distilled water? 7 -7 10 1 x 10^-7
7
How many neutrons are in the isotope carbon-14? 6 8 12 14
8
What is a single-replacement reaction? A reaction in which two or more substances react to form a single substance. A reaction in which one element takes the place of another element in the compound. A reaction in which a compound breaks down into two or more simpler substances.
A reaction in which one element takes the place of another element in the compound.
What happens if the hypothesis does not support the concluded data of an experiment?
A scientist can revise or propose a new hypothesis, then a new experiment can be conducted.
Which of the following is a general equation for a synthesis reaction? AB---->A+B A+B---->AB A+BC---->B+AC
A+B---->AB
How are science and technology related? Technology is a branch of natural science Advances in science may lead to advances in technology and vise versa Science is a branch of technology
Advances in science may lead to advances in technology and vise versa
Which statement about subatomic particles is true? An electron has far less mass than either a proton or neutron neutrons have no charge and no mass Unlike protons or neutrons, electrons have no mass
An electron has far less mass than either a proton or neutron
Which statement about electrons and atomic orbitals is NOT true? An electron has the same amount of energy in all orbitals An orbital can contain a maximum of two electrons An electron cloud represents all the orbitals in an atom An atom's lowest energy level has only one orbital
An electron has the same amount of energy in all orbitals
What is the foundation of space science?
Astronomy
Which of the following statements is true about what happens during a chemical reaction? Bonds of the reactants are formed, and bonds of the products are broken. Bonds of the reactants are broken, and bonds of the products are formed. The bonds of both the reactants and the products are formed. The bonds of both the reactants and the products are broken.
Bonds of the reactants are broken, and bonds of the products are formed.
What do solutions and colloids have in common? Both are made up of only elements Both appear homogeneous Both appear heterogeneous Both have large particles that will settle out
Both appear homogeneous
The law states that the volume of a gas is directly proportional to its temperature in kelvins if the pressure and the number of particles is constant is Boyle's Law Bose's Law Einstein's Law Charles's Law
Charles's Law
___________ properties can be observed only when the substances in a sample of matter are changing into different substances.
Chemical
What are the two main areas of physical science?
Chemistry and physics.
Which of the following takes place during a redox reaction? Electrons are gained only Electrons are lost only Elections are both gained and lost
Elections are both gained and lost
Which statement accurately represents the arrangement of electrons in Bohr's atomic model? Electrons vibrate in fixed locations around the nucleus Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level Electrons travel randomly in the relatively large space outside the nucleus
Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level
Who provided evidence for the existence of a nucleus in an atom? John Dalton J. J. Thomson Democritus Ernest Rutherford
Ernest Rutherford
Which of the following Group 7A elements is the most reactive? Cl (chlorine_ I (iodine) F (fluorine) Br (bromine)
F (fluorine)
What are repeatable observations know as?
Facts
True or False: Magnesium is found in freshwater lakes.
False
What are line graphs useful for?
For showing changes that occur in related variables. The manipulated variable is plotted on the x-axis and the responding variable is plotted on the y-axis.
What is the foundation of Earth Science?
Geology.
How was Bohr's atomic model similar to Rutherford's model? It assigned energy levels to electrons It described electron position in terms of the electron cloud model It described how electrons gain or lose energy It described a nucleus surrounded by a large volume of space
It described a nucleus surrounded by a large volume of space
What happens to the equilibrium when the pressure is increased? It favors formation of reactants It favors formation of products It does not change It is conserved
It does not change
How does a balanced equation show that mass is conserved? It has the same coefficients on both sides of the equation. It has the same element symbols on both sides of the equation. It has the same number of atoms of each element on both sides of the equations. It has the same number of molecular formulas on both sides of the equation.
It has the same number of atoms of each element on both sides of the equations.
What are data tables useful for?
It is the simplest way to organize data. Data tables relate the manipulated variable and the responding variable.
In a chemical reaction, an iron atom became Fe^2+. What happened to the iron atom? It lost electrons and was oxidized. It lost electrons and was reduced. It gained electrons and was oxidized. It gained electrons and was reduced.
It lost electrons and was oxidized.
What is the formula for the ionic compound lithium oxide? LiO Li2O LiO2 Li2O3
Li2O
What do experiments begin with?
Making observations.
Write the formula for the compound dinitrogen pentoxide.
N2O5
Does curiosity achieve answers?
No. Curiosity provides questions, not answers.
What branches is natural science divided into?
Physical, Earth and space, life science.
Write the name for the compound K2O.
Potassium oxide.
Which statement about subatomic particles is NOT true? Protons and neutrons have almost the same mass Protons and electrons have opposite charges Unlike protons and electrons, neutrons have no charge Protons and neutrons have the same charge
Protons and neutrons have the same charge
What does science begin and end with?
Science begins with curiosity and ends with discovery.
Which of the following statements is true about scientific theories? Scientific theories become scientifc laws. Scientific theories are never proven. Scientific theories become hypotheses. Scientific theories summarize patterns found in nature.
Scientific theories are never proven.
What are circle graphs useful for?
Shows how a part or share of something relates to the whole.
What is the study of science divided into?
Social and natural science.
What is the difference between an atom in the ground state and an atom in an excited state? The atom in an excited state has more energy and is less stable than the atom in the ground state The atom in an excited state has one more electron that the atom in the ground state. The atom in an excited state has one fewer electron than the atom in the ground state.
The atom in an excited state has more energy and is less stable than the atom in the ground state
Which of the following best describes how the attractive forces of the molecules in a solid compare to a liquid? The attractive forces are the same in a solid and liquid. The attractive forces are stronger in a liquid. The attractive forces are stronger in a solid. The attractive forces of a solid allow the particles to move freely while the liquid molecules vibrate around a fixed point.
The attractive forces are stronger in a liquid
If the temperature and the number of particles remains the same in a container but the volume decreases, what will happen to the pressure and which law supports that conclusion? The pressure will decrease, supported by Boyle's Law. The pressure will increase, supported by Boyle's Law. The pressure will decrease, supported by Charles's Law. The pressure will increase, supported by Charles's Law.
The pressure will increase, supported by Boyle's Law.
A student dissolved equal amounts of salt in equal amounts of warm water, room-temperature water, and ice water. Which of the following is true? The salt dissolved most quickly in the warm water. The salt dissolved most quickly in the room-temperature water. The salt dissolved most quickly in the ice water.
The salt dissolved most quickly in the warm water.
What happens if a scientific theory fails to explain new facts and discoveries?
The theory must be revised or replaced.
A student had a sample of pure water and added an unknown substance to it. The student noticed that the hydroxide ion concentration in the solution increased as the substance was added. What can the student conclude about the new solution? The unknown substance is an acid The unknown substance is a base The unknown substance is a salt The unknown substance is neutral
The unknown substance is a base
Rutherford's gold foil experiment provided evidence for which of the following statements? There is a dense, positively charged mass in the center of an atom Alpha particles have a positive charge Gold is not as dense as previously thought
There is a dense, positively charged mass in the center of an atom
Which of the following statements correctly describes the substance with the formula KI? Molecules of potassium iodide contain one atom of potassium and one atom of iodine? There is a one-to-one ratio of potassium ions to iodide ions Potassium iodide is a molecular compound
There is a one-to-one ratio of potassium ions to iodide ions
Which statement is true about oxygen-17 and oxygen-18? Their atoms have an identical mass They are isotopes of oxygen They have the same mass number
They are isotopes of oxygen
What are bar graphs useful for?
To compare a set of measurements, amounts, or changes.
Why do scientists use controlled experiments?
To show the relationship between a manipulated variable and a responding variable.
What is main goal of any scientific method?
To solve a problem or to better understand an observed event.
True or False: Magnesium is dangerous to look at when it burns.
True
True or False: Magnesium is used in photography, fireworks, and flares.
True
Which of the following provides the best analogy for an electron in an atomic orbital? a bee moving from flower to flower in a garden a bee trying to escape from a closed jar an ant crawling on the surface of a leaf
a bee trying to escape from a closed jar
Which of the following clocks is most precise? a clock with only one hand to measure the hour. a clock with only one hand to measure the minutes. a clock with a hand to measure the hour and a hand to measure the minutes. a clock with a hand to measure the hour, a hand to measure the minutes, and a hand to measure the seconds.
a clock with a hand to measure the hour, a hand to measure the minutes, and a hand to measure the seconds.
Which of the following is a heterogeneous mixture? water in a swimming pool sugar water a jar of mixed nuts stainless steel
a jar of mixed nuts
Alkali metals, alkaline earth metals, and aluminum all form ions with positive charges equal to the atomic number the group number a polyatomic ion an ionic bond
a polyatomic ion
What is a peer review? a process in which only close friends of a scientist review the scientist's work a process in which scientists examine other scientists' work a process in which scientists copy other scientists' work a process in which scientists keep their work a secret
a process in which scientists examine other scientists' work
A acid can be defined as a proton acceptor a proton donor neither a proton donor nor a proton acceptor both a proton donor and a proton acceptor
a proton acceptor
What is a statement that summarizes a pattern found in nature. a scientific law a fact a scientific theory a hypothesis
a scientific law
Forces of attraction limit the motion of particles most in a solid a liquid a gas
a solid
Typically, atoms gain or lose electrons to achieve an exchange of energy ionization a stable electron configuration vaporization
a stable electron configuration
Which of the following most accurately represents John Dalton's model of the atom? a tiny, solid sphere with an unpredictable mass for a given element a hollow sphere with a dense nucleus a tiny, solid sphere with a predictable mass for a given element a sphere that is hollow throughout
a tiny, solid sphere with a predictable mass for a given element
The atomic mass of an element is the sum of the protons and neutrons is one atom of the element twice the number of protons in one atom of the element a ratio based on the mass of a carbon-12 atom a weighted average of the masses of an element's isotopes
a weighted average of the masses of an element's isotopes
Which group of elements has two valence electrons in their atoms? transition metals metal alloys alkali metals alkaline earth metals
alkaline earth metals
Which group of elements has two valence electrons in their atoms? transition metals transitive metals alkaline earth metals alkali metals
alkaline earth metals
How to scientists communicate the results of investigations? by publishing articles in scientific journals by giving talks at scientific conferences by exchanging e-mails all of the above
all of the above
Water is a compound because it can be broken down into simpler substances always has two hydrogen atoms for each oxygen atom is made of water atoms joined together all of the above
all of the above
Which of the following factors affects the pressure of an enclosed gas? temperature volume number of particles all of the above
all of the above
The unit for atomic mass is gram amu pound none of the above
amu
Which of the following gases emit colors when an electric current is applied? hydrogen and helium argon and krypton fluorine and chlorine oxygen and nitrogen
argon and krypton
The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided? element atom electron molecule
atom
One twelfth the mass of a carbon-12 atom is used to define a(n) atomic number atomic mass mass number atomic mass unit
atomic mass unit
Moving left to right across a row of the periodic table, which of the following values increases by exactly one from element to element? isotope number atomic number atomic mass unit mass number
atomic number
The number of protons in one atom of an element is that element's mass number balanced charge atomic number isotope
atomic number
To find the number of neutrons in an atom, you would subtract mass number from atomic number atomic number from mass number atomic number from electron number isotope number from atomic number
atomic number from mass number
In a compound, chemical energy is contained in the nuclei of the atoms unbonded electrons bonds movement of the electrons
bonds
If an unknown substance cannot be broken down into simpler substances, it is a compound an element made of one kind of atom both and element and made of one kind of atom
both and element and made of one kind of atom
What are solutions that are resistant to large changes in pH? electrolytes strong acids buffers strong bases
buffers
A girl tasted each of the following foods. Which of the following would NOT taste acidic to her? lime tomato orange celery
celery
Which of the following is not a clue that a chemical change has occurred? change in color production of a gas formation of a precipitate change in shape
change in shape
Which element has 17 protons, 17 electrons, and 18 neutrons? argon chlorine hydrogen selenium
chlorine
The type of graph used to show how a part of something relates to the whole is which of the following? circle graph bar graph line graph direct proportion
circle graph
The rate that a solid solute dissolves in a liquid solvent depends on the frequency and energy of the ___________ between the particles of the solute and solvent.
collisions
When Mendeleev organized elements in his periodic table in order of increasing mass, elements with similar properties were in the same ___________.
column
When a physical change in a sample occurs. which of the following does not change? shape temperature volume composition
compostion
Which of the following are pure substances? solutions compounds homogeneous mixtures colloids
compounds
The total amount of energy before and after a chemical reaction is the same. Thus, the energy is created destroyed conserved same as the mass
conserved
J.J. Thomson's experiments provided evidence that an atom is the smallest particle of matter contains negatively charged particles has a negative charge has a positive
contains negatively charged particles
Which type of experiment involves changing only one variable at a time? manipulated constant controlled master
controlled
Which of the following has the highest viscosity? corn syrup milk water orange juice
corn syrup
Which type of bond is held together by the attractions between the protons in the nucleus and the shared electrons? ionic covalent metallic unstable
covalent
If the mass of an object stays constant but the volume increases, then the density increases decreases stays constant increases at first, but then decreases
decreases
The phase change in which a substance changes from a gas directly to a solid is condensation vaporization deposition sublimation
deposition
Which of the following phase changes is an exothermic change? sublimation deposition vaporization melting
deposition
Which of the following phase changes is an exothermic change? sublimation deposition vaporization melting
deposition
What is the relationship in which the ratio of the manipulated variable and the responding variable is constant? inverse proportion direct proportion slope interdependent
direct proportion
A substance dissolves in water by breaking up into smaller pieces. These pieces of the same substances spread throughout the water. This process is known as ____________.
dispersion
What method can be used to separate parts of a liquid mixture when the entire mixture can pass through a filter? filtration distillation straining screening
distillation
During a phase change, the temperature of a substance increases decrease does not change increases or decreases
does not change
When magnesium carbonate, MgCO2, reacts with nitric acid, HNO3, magensium nitrate and carbonic acid form. Carbonic acid then breaks down into water and carbon dioxide. Which two types reactions take place in this process? synthesis and decomposition single-replacement and combustion double-replacement and decompostion
double-replacement and decompostion
Most metals are ______, __________, and are ________ ________ of ________ _______
ductile, malleable, good conductors of electric current
During the formation of a solution, energy is _______. either released or absorbed neither released nor absorbed released only absorbed only
either released or absorbed
Which subatomic particle has a negative charge? electron alpha particle neutron proton
electron
In a polar covalent bond, electrons are not shared equally between atoms electrons are shared equally between atoms a cation is bonded to an anion
electrons are not shared equally between atoms
A substance that is made up of only one kind of atom is a(n) compound homogeneous mixture element solution
element
Mendeleev's periodic table was useful because it enable scientists to predict properties of unknown ___________.
elements
Cooking requires addition of energy to the chemical reactions that are taking place. The chemical reactions involved in cooking can be described as
endothermic
During a(n) __________ change, a system absorbs energy from its surroundings.
endothermic
First aid kits commonly contain a package that gets very cold when the chemicals inside the package are mixed together, and it can be used as an ice pack for injuries. Which of the following describes the type of chemical reaction taking place? endothermic reaction, because energy is absorbed. endothermic reaction, because energy is released. exothermic reaction, because energy is absorbed exothermic reaction, because energy is released
endothermic reaction, because energy is absorbed.
An atom in which an electron has moved to a higher energy level is in a(n) _____________ state.
excited
In terms of energy, how would you classify the following chemical reaction? 2Cu+O2----->2CuO+315 kJ endothermic exothermic both endothermic and exothermic neither endothermic nor exothermic
exothermic
What are the common properties of bases?
feels slippery, tastes bitter, changes colors of indicators
A member of the boron family has three valence electrons, while a member of the nitrogen family has none five four three
five
During which phase change does the arrangement of water molecules become more orderly? melting freezing boiling condensing
freezing
During vaporization, a substance changes from a liquid to a(n) _____.
gas
Collisions of helium atoms with the walls of a closed container cause condensation gas pressure a decrease in volume an overall loss in energy
gas pressure
Which of the following is malleable? glass pottery ice gold
gold
A salt is dissolved in water, which has a boiling point of 100C. The boiling point of the solution will be _______. greater than 100C less than 100C exactly equal to 100C exactly equal to 0C.
greater than 100C
Which of the following groups contain three elements with stable electron configurations? lithium; krypton; argon xenon; neon; boron helium; xenon; neon
helium; xenon; neon
A mixture that appears to contain only one substance is a(n) homogeneous mixture heterogeneous mixture compound element
homogeneous mixture
A base is defined as a compound that produces hydroxide ions in solution hydrogen ions in solution hydronium ions in solution sodium ions in solution
hydroxide ions in solution
A chunk of limestone, which is calcium carbonate, reacts with an acid at a certain rate. If the limestone were crushed, the rate of the reaction between the limestone and the acid would _________
increase
The temperature and volume in a closed container of gas remain constant. If the number of particles gas increases, the gas pressure will increase decrease remain constant cause a decrease in kinetic energy of the particles
increase
Ionization energies tend to decrease from left to right across a period increase form the top of a group to the bottom increase from left to right across a period decrease from the bottom a group to the top
increase from left to right across a period
As you move from left to right across a period, the number of valence electrons increases stays the same increases and then decreases decreases
increases
In general, if temperature of a chemical reaction increases, the reaction rate increases decreased remains the same cannot be predicted
increases
Among the alkali metals, the tendency to react with other substances does not vary among the members of the group increases from top to bottom within the group varies in an unpredictable way within the group
increases from top to bottom within the group
The solubility of carbon dioxide gas in water can be increased by increasing the temperature agitating the mixture increasing the pressure using more solvent
increasing the pressure
The name iron(II) indicates that a compound contains ion ions with an 11+ charge iron ions with a 2+ charge iron ions with a negative charge
iron ions with a 2+ charge
Dissolving sugar and drink mix into a pitcher of water is considered a physical change because the elements combine to form a compound the sugar can no longer be separated from the water it does not change the chemical composition of the solution a reaction takes place during the mixing process
it does not change the chemical composition of the solution
Which statement best describes Rutherford's model of the atom? It is like an avocado with the pit representing the nucleus it is like an aquarium with swimming fish representing positive charges it is like a fried egg with the yolk representing the nucleus it is like a huge stadium with a positively charged marble at the center
it is like a huge stadium with a positively charged marble at the center
The __________ theory of matter states that all particles of matter are in constant motion.
kinetic
Which of the following elements are non-reactive because their outer electron energy levels are full? aluminum carbon krypton uranium
krypton
Compared to a gas, the molecules of a solid at a given temperature have more kinetic energy less kinetic energy smaller atoms larger atoms
less kinetic energy
What are the three branches of natural science?
life, earth and space, physical science
In Niels Bohr's model of the atom, electrons move like balls rolling down a hill like planets orbiting the sun like popcorn in a popcorn popper like beach balls on water waves
like planets orbiting the sun
Matter that has a definite volume but no definite shape is a liquid solid gas plasma
liquid
Fluorine, F, forms a binary ionic compound with lithium, Li. What is the name of this compound? fluorine lithide lithium fluoride lithium fluorine
lithium fluoride
Which of the following will cause a decrease in gas pressure in a closed container? lowering the temperature reducing the volume adding more gas both lowering the temperature and reducing the volume
lowering the temperature
When magnesium metal, Mg, reacts with oxygen, O2, the product of the reaction is MgO, which is called di-magnesium oxide magnesium oxide magnesium dioxide
magnesium oxide
In which step of the scientific method is information gained through the senses? drawing conclusions making observations analyzing data revising a hypothesis
making observations
Mendeleev arranged the known chemical elements in a table according to increasing atomic number number of electrons number of protons mass
mass
The heat of fusion for water is the amount of energy needed for water to freeze boil melt evaporate
melt
Which of the following is not a pure substance? milk oxygen water carbon dioxide
milk
What is the measurement of 6 centimeters equal to?
milli=1000, centi=100. 1000/100=10. 6*10=60
When a doctor is measuring liquid medicine for a small child, which unit would the doctor likely use? liter milliliter grams milligrams
milliliter
A paper airplane used to study wing designs is an example of? theory hypothesis model scientific method
model
Compared with Group 2A elements, Group 6A elements have more atoms in the ground state more valence electrons more isotopes fewer valence electrons
more valence electrons
Which general statement does NOT apply to metals? Most metals are ductile Most metals are malleable Most metals are brittle Most metals are good conductors of electric current
most metals are brittle
Group 7A of the periodic table contains the most reactive nonmetals most reactive metals least reactive nonmetals least reactive metals
most reactive nonmetals
The glowing of a neon light is caused by electrons emitting energy as they move from lower to higher energy levels collide with other electrons move from higher to lower energy levels collide with the nucleus
move from higher to lower energy levels
The results of Rutherford's gold foil experiment demonstrated that the ___________ occupies a very small amount of the total space inside an atom.
nucleus
If element Q has 11 protons, its atomic ___________ is 11.
number
Water has a higher boiling point than expected because of the strong attractions between polar water molecules there is so much water vapor in the atmosphere water molecules are not very massive
of the strong attractions between polar water molecules
Which of the following is not one of the main ideas of science? the universe is very old and very large forces cause changes in motion energy can be transferred from one form to another, but it can never be destroyed one of the main branches is biology
one of the main branches is biology.
When an atom is in an excited state, one or more electrons have moved from the ground state to a higher energy level one or more electrons have moved out of the first energy level to the second energy level there are more protons than neutrons in the nucleus all the electrons move up one energy level
one or more electrons have moved from the ground state to a higher energy level
In order for a solution to form, _________. one substance must dissolve in another one solid must dissolve in a liquid the solvent must be water a gas must dissolve in a liquid
one substance must dissolve in another
The region in which an electron is most likely to be found is called a(n) _____________.
orbital
Flammability is a material's ability to burn in the presence of oxygen nitrogen hydrogen carbon dioxide
oxygen
The pattern of repeating properties of elements revealed in the periodic table is known as the ______________.
periodic law
A(n)________ occurs when a material changes shape or size but the composition of the material does not change.
physical
All of the following affect dissolving rates of a solid in a liquid except temperature pressure surface area stirring
pressure
What do scientists use to predict the locations of electrons in atoms? probability algebra geometry ratios and proportions
probability
The periodic table organizes elements based on both physical and chemical properties. Which element below will have properties similar to calcium (Ca)? hydrogen (H) oxygen (O) radium (Ra) uranium (U)
radium (Ra)
Measuring how quickly a reaction disappears is one way to measure the ________ of the reaction.
rate
Which of the following is NOT common property of bases? feels slippery tastes bitter reacts with metals changes colors of indicators
reacts with metals
In a periodic table, a set of properties repeats from element to element group to group column to column\ row to row
row to row
One way to determine the degree of saturation of a solid-liquid solution is to drop a crystal of the solute into the solution. If the crystal sits at the bottom of the container, the solution is saturated unsaturated supersaturated concentrated
saturated
What is a system of knowledge and the methods used to find that knowledge? science technology measurement curiosity
science
Two factors that determine whether a molecule is polar are the types of atoms in the molecule and the _____________ of the molecule.
shape
A mixture can be classified as a solution, suspension, or colloid based on the number of particles it contains size of its largest particles color of its particles size of its smallest particles
size of its largest particles
Which of the following is NOT a branch of natural science? life science earth and space science physical science social science
social science
Which of the following are example of strong electrolytes? strong and weak bases strong acids and strong bases weak acids and weak bases pure water and buffers
strong acids and strong bases
The phase change in which a substance changes from a solid to a gas or vapor without changing to a liquid first is sublimation deposition vaporization melting
sublimation
A solution that contains more solute than it would normally hold at that temperature is said to be saturated unsaturated supersaturated concentrated
supersaturated
An iron fence is left unpainted, and it reacts with the oxygen in the air, forming rust. The formation of rust is an oxidation-reduction reaction, but it is also an example of a(n) __________ reaction
synthesis
Boyle's Law states that the volume of a gas is inversely proportional to its pressure if the temperature and number of particles is constant temperature reaches absolute zero number of particles decreases temperature and number of particles are doubled.
temperature and number of particles is constant
Which factors affect dissolving rates of a solid in a liquid?
temperature, surface area, stirring
Which of the following is a typical property of an ionic compound? low melting point poor conductor of electric current when melted tendency to shatter when struck all of the above
tendency to shatter when struck
A student finds that after applying a certain lotion to a scar, the scar is gone in two days without any side effects. He asks several of his friends who also have scars to use the same lotion. Which step of the scientific method is he using? gathering data stating the problem testing a hypothesis drawing a conclusion
testing a hypothesis
Democritus thought that matter was made of tiny particles of earth, air, fire, and water that could be divided that could not be divided
that could not be divided
The usefulness of Mendeleev's periodic table was confirmed by the discovery of subatomic particles the discovery of elements with predicted properties the discovery of the nucles
the discovery of elements with predicted properties
What does the electron cloud model describe? the most likely locations of electrons in atoms the precise locations of electrons in atoms the mass of the electrons in an atom
the most likely locations of electrons in atoms
In an electron-dot diagram, the symbol for an element is used to represent the nucleus the nucleus and all electrons the nucleus and valence electrons the nucleus and all non-valence electrons
the nucleus and all non-valence electrons
The tendency of an element to react is closely related to its atomic mass attractions between its atoms the number of valence electrons in atoms of the element
the number of valence electrons in atoms of the element
A student has a sample with a hydrogen ion concentration of 1 x 10^-4. What happens to it if the hydrogen ion concentration is increased? the hydroxide ion concentration increases the solution becomes more basic the pH increase the pH decreases
the pH decreases
The result of a chemical reaction is called the reactant the element the compound the product
the product
According to John Dalton's observations, when elements combine in a compound, the ratio of their masses is always the same each element contributes an equal number of atoms their volumes are always equal their masses are always equal
the ratio of their masses is always the same
When the forward and reverse paths of a change occur at the same rate, the system is conserved the system is in equilibrium the change must be physical the change must be chemical
the system is in equilibrium
An industrial process makes calcium oxide by decomposing calcium carbonate. Which of the following is NOT needed to calculate the mass of calcium oxide that can be produced from 4.7 kg of calcium carbonate. the balanced chemical equation molar masses of the reactants molar masses of the products the volume of the unknown mass
the volume of the unknown mass
Which of the following cannot be determined by analyzing the periodic table? the number of protons the chemical symbol for each element the year the element was discovered then number of electron energy levels
the year the element was discovered
In the compound MgCl2, the subscript 2 indicates that there are two magnesium ions for each ion of chlorine the chloride ion is twice the size of the magnesium ion there are two chloride ions for each magnesium ion
there are two chloride ions for each magnesium ion
What part of Rutherford's investigations demonstrated that the Thomson model was not accurate? They showed that atoms have an overall negative charge they showed that all particles of an atom are the same size they showed that electrons and protons make up the mass of the atom they showed that the atoms have a dense nucleus
they showed that the atoms have a dense nucleus
The formation of an ionic bond involves the transfer of electrons transfer of neutrons transfer of protons transfer of electrons
transfer of electrons
The elements most likely to form more than one type of ion are the transition metals alkali metals halogens alkaline earth metals
transition metals
In the name carbon dioxide, the prefix of the second word indicates that a molecule of carbon dioxide contains two carbon atoms two oxygen atoms an ionic bond a polyatomic ion
two oxygen atoms
A measurement must include both a number a a(n)
unit
The phase change that is the reverse of condensation is freezing sublimation vaporization melting
vaporization
A graph representing Charles's Law shows that the _________ of a gas increases at the same rate as the temperature of the gas.
volume
To calculate the molarity of a solution, you need to know the moles of solute and the volume of the solvent volume of the solution mass of the solution volume of the solute
volume of the solution
To calculate the molarity of a solution, you need to know the moles of solute and the ______. volume of the solvent volume of the solution mass of the solution volume of the solute
volume of the solution
Materials can be classified as solids, liquids, or gases based on whether their shapes and _________ are definite or variable.
volumes
A substance has a melting point of 0C and a boiling point of 100C. The substance is most likely water hydrogen gold salt
water
Which of the following is a chemical change? ice melting ice being carved water boiling water breaking down into hydrogen and oxygen
water breaking down into hydrogen and oxygen
Because water molecules are polar, and carbon dioxide molecules are nonpolar, water has a higher boiling point than carbon dioxide does water has a lower boiling point than carbon dioxide does carbon dioxide cannot exist as a soild
water has a higher boiling point than carbon dioxide does
Which of the following is useful for making mold because it has a low melting point? wood metal clay wax
wax
A compound has a pH of 6 in solution, where very little of it has ionized. The compound is a weak base strong base weak acid strong acid
weak acid
To determine the atomic mass of an element, you would take a(n) _______________ average of the isotopes that make up that element.
weighted