Chemistry
Ne
Neon (noble gas)
Lewis Structure:
Representation of how atoms are connected, including lone pairs of electrons
Chemical formula:
Shows only types and ratios of atoms present
What is the correct systematic name for the compound Na2CO3?
Sodium carbonate
Which of the following are three-dimensional representations of a molecule?
Space-filling model and Wedge-dash representation
A liquid will have a higher boling point if its intermolecular attractions are _________.
Stronger
Resonance forms are Lewis Structures that have the same relative placement of _________ but a different arrangement of ___________.
atoms electrons
If a chemical reaction is reversible, it occurs in both the forward and reverse directions at once, allowing the system to reach a(n) _________ if the system is closed.
equilibrium
HDPE:
fencing, milk containers, opaque containers, heavy-duty pipes
A chemical reaction is process whereby substances called _______________ are transformed into different substances called ________________
first blank: reactants Second blank: products
penta-
five
Place the reactions that involve the production of H2 in a reformer in the correct order.
1. CH3OH(l) -> CH3OH(g) 2. CH3OH(g) -> CO(g) + 2H2(g) 3. CO(g) + H2O(g) -> CO2(g) + H2(g)
Place the steps of drawing a Lewis structure in the correct order, starting with the first step at the top of the list
1. Count the number of outer electrons contributed by each atom. 2. Add the valence electrons contributed by each individual atom to determine the total number of outer electrons for the species. 3. Arrange the outer electrons in pairs around the contributing atoms. 4. Ensure that each atom has a full outer shell.
Rank following solutions in order of increasing acidity based on pH values (least to greatest)
1. Household ammonia 11.5 2. Seawater 8.2 3. Rainwater 5.3 4. Tomato juice 4.1
Which of the following options correctly interpret the symbol 224/86 Rn?
1. Rn is the symbol of the element 2. The number 86 is the atomic number of the isotope 3. 86 represents the number of protons in the nucleus
Match. Solutions to description of relative acidity
1. pH of A = 3; pH of B = 4 - A is 10 times more acidic 2. pH of A=8; B=4 - B is 10000 times more acidic 3. pH of A=6; B=8 - A is 100 times more acidic 4. pH of A=10.5; B=7.5 - B is 1000 times more acidic
Which of the following options correctly describe the term current?
1. the unit of current is the ampere 2. current is the rate of electron flow in a cell
Place the steps for the production of ethanol from corn in order, with the first step at the top of the list.
1.) Corn kernels are mixed with water. 2.) Enzymes break down starches into glucose. 3.) Yeast fermentation converts sugars into ethanol. 4.) The mixture is distilled
most electronegative element
Fluorine
Which of the following statements correctly describe the atomic number of an element?
Each element has its own unique atomic number The atomic number is equal to the number of protons in the nucleus
True or false: Resonance forms are different possible structures for the same species that interconvert rapidly
False
Elements in group 7A are called: _________________, whereas elements in grouo 8A are called: ________________ gases
First blank: halogens Second Blank: noble gases
Which of the following molecules is polar?
NH3
Which of the following are elements:
Na, Cu, O2
Which of the following formulas for ionic compounds are written correctly?
NaNO3 CaCO3
What is the term used to describe a condition in which a dynamic system has no net change in concentration of the major species involved?
Steady state
In a molecular substance, the covalent bonds between the atoms hold the individual molecule together as a unit and may be referred to as ________ forces. The nonbonding forces of attraction between one individual molecule and another one are called ________ forces.
intramolecular;intermolecular
Cu+
(I)
Cr 2+
(II)
Fe 3+
(III)
Which of the following are forms of potential energy?
--- The energy stored in the chemical bonds of a compound. --- The energy of an object suspended above the ground.
Which of the following are natural polymers?
-Cellulose -Proteins
The following are the steps seen when a Newton's cradle is used. Place them in the correct order, with the first step at the top.
1.) One ball is lifted by hand, giving it potential energy 2.) The ball is released, converting potential energy into kinetic energy as it falls. 3.) The falling ball strikes the unmoving balls, and kinetic energy is transferred through them to the ball on the opposite end. 4.) The opposite ball swings upward, converting its kinetic energy to potential energy.
Tetrahedral
109.5
Co:
27 protons and 27 electrons
A boron (B) atom has _________ valence electrons
3
Carbon is in Group 14. How many valence electrons does carbon have? In order to attain a full octet in its outer shell it will therefore form _______ covalent bonds.
4:4
Xe:
54 protons and 54 electrons
Given the symbol 210/82 PB, match each number with the correct meaning
82: number of protons in the nucleus 210: mass number 128: number of neutrons in the nucleus.
F:
9 protons and 9 electrons
Complete combustion
A combustion reaction in which the only products are carbon dioxide and water CO2 and H20
Which of the following options correctly describe elements and compounds?
A compound contains two or more different elements There are many more known compounds than elements Elements and compounds are pure substances
Which of the following options correctly describe how to name a compound containing two nonmetals?
A greek numerical prefix is always used when more than one atom is present to indicate the number of atoms of each element in the compound The name of the first element remains unchanged, except for the addition of a prefix where appropriate The second element is named with its roots and the suffix -ide
Which of the following statements correctly defines a molecule?
A molecule is an independent structure consisting of two or more atoms chemically bonded together.
Which of the following statements correctly describes a photon? Select all that apply:
A photon is a particle of electromagnetic radiation Matter cannot absorb or emit a fraction of a photon
Which of the following options correctly describe a polymer?
A polymer is made up of repeating units called monomers Polymers have high molecular masses The prefix poly indicates that a polymer is made up of many smaller units
Element
A pure substance made of only one kind of atom
Pure substance:
A sample of matter, either a single element or a single compound, that has definite chemical and physical properties hydrogen gas, water, a pure silver coin
Electron
A subatomic particle that has a negative charge
Proton:
A subatomic particle that has a positive charge and that is found in the nucleus of an atom
Neutron:
A subatomic particle that has no charge and that is found in the nucleus of an atom
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
Atoms bond in order to fill their valence shell of electrons. Most elements strive for a total of __________ such electrons while hydrogen strives for a total of __________.
Answer #1: 8 Answer #2: 2
Lewis structures are used to represent covalent compounds. Shared electron pairs are shown either as pairs of __________________ or lines and only ________________ electrons are shown.
Answer #1: dots Answer #2: valence
A true ___ is made up of several galvanic cells that are wired together battery
Battery
Which of the following formulas for ionic compounds are correct?
Ca3N2 CaO
Which of the following formulas for ionic compounds are correct?
CaO Ca3N2
Which of the following options correctly describe the chemical symbols for elements?
Chemical symbols are also called atomic symbols Chemical symbols are abbreviations for elements named for properties, places, planets, and people.
Ci:
Chlorine (halogen)
In the U.S. the primary energy source used to generate electricity is __
Combustion of fossil fuels
Cu:
Copper (cuprum)
Rank the following forces of attraction from the strongest to weakest.
Covalent bonds Intermolecular forces
The raw material used to synthesize polymers is:
Crude oil
Correctly order the steps required to determine the shape of a molecule, starting with the first step.
Determine the number of outer electrons associated with each atom in the molecule Arrange the outer electrons in pairs, ensuring that all atoms other than hydrogen obey the octet rule Determine the shape of the molecule by examining the position of the bonding and nonbonding electron pairs with respect to each other.
What type of forces are a result of an attraction between molecules due to a distortion in the electron cloud, which causes an uneven distribution of negative charge?
Dispersion forces
E
Energy of a photon
The speed of a wave is determined by multiplying the ______________ of the wave by its wavelength. In a vacuum all electromagnetic radiation travels at a constant speed, the speed of _________.
Frequency, light.
The _______ zone is the intersection of healthy ecosystems, healthy economies, and healthy communities.
Green
Which of the following options correctly describe the physical properties of HDPE?
HDPE is more rigid than LDPE and HDPE is stronger than LDPE
Which of the following statements correctly describe isotopes?
Isotopes have different numbers of neutrons Each element's atomic mass is a weighted average of the masses of the element's isotopes.
Resonance forms are correctly defined as:
Lewis structures for the same species that differ in the placement of electrons
The intermolecular forces that cause polyethylene to be a solid material are ________ forces
London dispersion
Which of the following options correctly describe activation energy?
Lower activation energy generally results in faster reactions Increasing temperature allows more particles to have sufficient energy to overcome the activation energy barrier.
Which of the following options correctly describe the mass number of an element?
Mass number is given by the sum of the protons and neutrons in the nucleus The mass number of a particular element may vary
Isomers have the same ___, but different ___
Molecular formula, structural formula
Which of the following options correctly reflects the relationship between molecular shape and the strength of dispersion forces?
Molecules with a large surface area have more points of contact and therefore experience stronger dispersion forces.
Zn 2+
None
Ozone decomposes into oxygen and atomic oxygen. Which of the following statements correctly describe the balanced equation for this reaction?
O2 is the product --
Which of the following gives the best explanation for why oil and water do not mix?
Oil does not mix with water because oil is nonpolar and water is polar
In a fuel cell, H2 is ___ to form 2H+ as it passes through the PEM. These H+ ions combine with O2 at the cathode in a ___ half-reaction to form H2O
Oxidized;reduction
What are the three components of the "triple bottom line" in business today?
Profitability Fairness to workers Environmental protection
Which color visible light will have the lowest energy photons?
Red - red light has the lowest frequency and longest wavelength in this series, and will therefore have the lowest energy photons
The oxidation state of an element
Reflects the way electrons are transferred during a reaction is determined by the way it is bonded Reflects its charge if it is present as an ion
Structural formula:
Representation of how atoms are arranged, omitting lone pairs of electrons
Predict the molecular shape for each of these compounds. Remember to consider all of the outer electrons before you make your choice. Methane Ammonia Sulfur trioxide Water Ozone Carbon dioxide
Tetrahedral Trigonal pyramidal Trigonal planar Bent Bent Linear
Which of the following options correctly describes the steps required to determine the shape of a molecule?
The Lewis structure of the molecule must be drawn first. Both bonding and nonbonding electron pairs must be considered. The shape of the molecule is dictated by the most stable arrangement of the outer electron pairs.
Which of the following options correctly describe a polyatomic ion?
The charge on a polyatomic ion belongs to the whole unit The atoms of a polyatomic ion are held together by covalent bonds
Which of the following options correctly describes the isotope Cr-53, if the element Cr (chromium) has an atomic number of 24?
The element contains 24 protons in its nucleus This isotope contains 29 neutrons in its nucleus
Activation energy is best described as __________
The energy required to initiate a chemical reaction.
Heat:
The energy transferred between objects that are at different temperatures Flow of energy between objects with a different molecular kinetic energies
Which of the following correctly describes how Roman numerals are used in naming and writing chemical formulas?
The ion designated Fe(III) has a charge of +3 A Roman numeral is included for any metal that can form more than one monatomic cation.
Which of the following options correctly describe the periodic table?
The periodic table contains the chemical symbols that represent the elements The elements in the periodic table are arranged based on similar chemical properties
What is the most common effect of increasing temperature on a chemical reaction?
The reaction rate will increase
Which of the following correctly reflects Avogrado's number?
There are 6.02x10^23 atoms in 12 grams of carbon -12
If the sign δ− is used to mark an atom in a covalent bond, it means that __________
This atom has a partial negative charge and this atom has a higher electron density
Frequency
V
incomplete combustion
When a fuel burns in insufficient oxygen, producing carbon monoxide as a toxic product. CO2, H2O, and CO
structural formula
a formula that shows the arrangement of atoms in the molecule of a compound. shows the placement of all atoms in the compound
Bond breaking:
absorbs energy (endothermic)
NH3
ammonia
The smallest unit of an element that can exist as a stable independent entity is a(n)
atom
A molecule is an independent structure composed of two or more ______ chemically bonded together
atoms
For any element, the atomic mass recorded on the periodic table is not a whole number since it is a(n) _____________ of the masses of its naturally occurring isotopes.
average
LDPE:
bubble wrap, grocery bags, plastic food wrap
Speed of light
c
The most abundant isotope of ________ is the internationally accepted standard for determining atomic mass.
carbon
Which of the following can be adjusted during the manufacturing process in order to create specific properties in a polymer?
chain length
The bond formed between two nonmetals is called a(n) _________ bond. This bond involves the __________ of one or more electron pairs between the atoms.
covalent; sharing.
The intermolecular attractions between nonpolar molecules such as hydrocarbons are called London ___________ forces
dispersion
An electric current is the net movement of _____
electrons
Einstein's equation E=mc2 means that matter can be converted into ___
energy
The measure of the amount of energy dispersed in a process is called:
entropy
Fuels formed by natural processes such as the decomposition of prehistoric organisms are called _____________ fuels
fossil
Reduction
gain of electrons
molecular formula
gives the ratio of elements in the compound
For the main-group elements (1A, 2A, etc.) the number of valence electrons for an element is equal to the ______ number for the element.
group
The time taken for half the radioactive nuclei in a sample to decay is called the __ of the radioisotope.
half-life
in a glass of coca cola, the cola is considered _________ mixture because its composition is ___________
homogenous;uniform
electromagnetic radiation
includes all the different types of light
nuclear radiation
includes alpha and beta particles as well as gamma radiation
Attractions between individual molecules are called __ attractions.
intermolecular
The central oxygen atom in H20 is surrounded by four electron pairs. These two lone pairs occupy more space than the bonding pairs, causing the bond angle in h20 to be ________ the ideal angle of 109.5 degrees.
less than
Oxidation
loss of electrons
In the formation of ionic compounds a metal will __________ electrons and a nonmetal will _________ electrons to form an ion with the same number of electrons as the nearest ____________ gas.
lost;gain;noble
δ−
marks the atom with the higher electronegativity
δ+
marks the atom with the lower electronegativity
Temperature:
measure of the average kinetic energy of the atoms/molecules in a substance
CH4
methane
In general, a lone pair occupies ___ space than a bonding electron pair, and will therefore ___ the bond angle between bonding pairs.
more;decrease
Which of the following are examples of fossil fuels
natural gas, coal, petroleum
mono-
one
o3
ozone
A(n) ____ cell converts light energy directly into electrical energy
photovoltaic
Mixture:
physical combination of two or more species salt water and gold-plated earrings
h
planck's constant
In a(n) ___ bond electrons are not shared equally, but are closer to the more electronegative atom
polar covalent
Water is a polar molecule because it contains ___ covalent bonds and adopts a(n) ___ shape
polar;bent
A unit that contains two or more elements covalently bonded together but that has an overall charge is called a(n) ________ ion. Many_________ compounds contain such units.
polyatomic;ionic
Stable isotopes differ from radioactive isotopes in their neutron-to-___ ratio
proton
Bond forming:
releases energy
During a chemical reaction, the number of different substances may or may not change, but the total mass of matter present _________
remains unchanged
A(n) ___________ pollutant is produced from chemical reactions involving one or more pollutants.
secondary pollutant
hepta-
seven
Hydrocarbons with only _______ bonds between carbon atoms are called alkanes.
single
Rank the following types of bonds from the longest to the shortest, starting with the longest bond on the top of the list.
single covenant bond double covenant bond third covenant bond
hexa-
six
Nucleus:
small region that contains almost all mass of the atom
c
speed of light
A sample of fuel is burned in oxygen, producing heat and light. Based on the first law of thermodynamics, which statement must be true?
the energy lost from the fuel and oxygen is equal to the energy of the heat and light.
The boiling point of a liquid is the temperature at which
the vapor pressure of the liquid equals the external pressure.
di-
two
H2O
water
λ
wavelength
The distance a wave travels during one cycle is called its ___________. This is usually measured as the distance between two ____________ or two troughs.
wavelength peaks
energy is the ability to do __________ or to produce _________
work;change
Which of the following ion combinations will result in an ionic compound that has a balanced number of positive and negative charges?
1. 2Li+ and S2 2. Na+ and Br- 3. Ca2+ and 2F
Match. Bond with difference in electronegativity.
1. O-H: 1.4 2. F-H: 1.9 3. S-Cl: .5 4. Si-F: 2.2
Using the attached graph, rank the use of coal, petroleum, hydroelectric, and nuclear power as energy sources in the United States in the year 2000. Place the least used energy source at the bottom.
1.) Petroleum 2.) Coal 3.) Nuclear 4.) Hydroelectric
Arrange the following types of radiation in order of increasing energy per photon, starting with the lowest energy radiation at the top of the list.
1.) Radio Waves 2.) Infrared Radiation 3.) Visible Light 4.) Gamma Rays
Rank the grades of coal by their desirabilities, starting with the most desirable coal at the top of the list.
1.) anthracite 2.) bituminous 3.) lignite
trigonal pyramidal
109.5
trigonal planar
120
The isotope Mg - 25 isotope has ________ protons and ___________ neutrons in the nucleus. Mg has an atomic number of 12.
12;13
The isotope Mg-25 has __________ protons and ____________ neutrons in its nucleus. Mg has an atomic number of 12
12;13
Ci has a mass number of 36
17 protons and 19 neutrons
Linear
180
K:
19 protons and 19 electrons
Rank the following common galvanic cells in order of increasing voltage, starting with the lowest voltage cell at the top of the list.
1. Ni-Cd 2. Alkaline 3. lead-acid 4. lithium-ion
Rank solutions in order of increasing acidity (least to greatest)
1. OH- = 1x10^1 2. H+ = 1x10^-8 3. H+ = 1x10^-3 4. OH- = 1x10^-12
Which of the following options correctly describe the factors that influence the ability of a nucleus to undergo fission?
1. The number of protons and neutrons influence the ability of a nucleus to undergo fission 2. Heavy nuclei may undergo fission if bombarded with high-energy neutrons 3. Small nuclei are less likely to undergo fission
Match. Type of radiation to resulting change in atomic number
1. a emission: atomic number decreases by 2 2. b emission: atomic number increases by 1 3. y radiation: atomic number remains unchanged
Match. Electrochemical cell with description.
1. anode: a site at which oxidation takes place and is therefore a source of electrons 2. cathode: a site at which reduction takes place and is therefore a site where electrons are received 3. electrode: an electrical conductor within a cell that serves as a site for a chemical reaction