Review Questions
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____ 1. Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates?
a. nitrogen
b. calcium
c. iodine
d. sodium
e. phosphorus
____ 2. Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus?
a. atomic mass
b. atomic weight
c. atomic number
d. mass weight
e. mass number
____ 3. What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons?
a. 15 daltons
b. 16 daltons
c. 30 daltons
d. 31 daltons
e. 46 daltons
____ 4. The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen?
a. The nitrogen atom has a mass number of approximately 7 daltons and an atomic mass of 14.
b. The nitrogen atom has a mass number of approximately 14 daltons and an atomic mass of 7.
c. The nitrogen atom has a mass number of 14 and an atomic mass of 7 grams.
d. The nitrogen atom has a mass number of 7 grams and an atomic number of 14.
e. The nitrogen atom has a mass number of 14 and an atomic mass of approximately 14 daltons.
____ 5. Different atomic forms of an element contain the same number of protons but a different number of neutrons. What are these different atomic forms called?
a. ions
b. isotopes
c. neutronic atoms
d. isomers
e. radioactive atoms
____ 6. Which of the following best describes the relationship between the atoms described below?
Atom 1 Atom 2
a. They are both radioactive.
b. They are both phosphorus cations.
c. They are both phosphorus anions.
d. They are both isotopes of phosphorus.
e. They contain 31 and 32 protons, respectively.
____ 7. One difference between carbon-12 and carbon-14 is that carbon-14 has
a. two more protons than carbon-12.
b. two more electrons than carbon-12.
c. two more neutrons than carbon-12.
d. A and C only
e. B and C only
____ 8. 3H is a radioactive isotope of hydrogen. One difference between hydrogen-1 ( H) and hydrogen-3 ( H) is that hydrogen-3 has
a. one more neutron and one more proton than hydrogen-1.
b. one more proton and one more electron than hydrogen-1.
c. one more electron and one more neutron than hydrogen-1.
d. two more neutrons than hydrogen-1.
e. two more protons than hydrogen-1.
____ 9. Two isotopes of the same element will have different numbers of
a. protons.
b. neutrons.
c. electrons.
d. protons and neutrons.
e. neutrons and electrons.
____ 10. The atomic number of neon is 10. Therefore, which of the following is correct about an atom of neon?
a. It has 8 electrons in its outer electron shell.
b. It is inert.
c. It has an atomic mass of 10 daltons.
d. A and B only
e. A, B, and C are correct.
____ 11. From its atomic number of 15, it is possible to predict that the phosphorus atom has
a. 15 neutrons.
b. 15 protons.
c. 15 electrons.
d. 8 electrons in its outermost electron shell.
e. B and C only
Use the figure below to answer the following questions.
____ 12. Which drawing depicts the electron configuration of oxygen ( O)?
a. Drawing A
b. Drawing B
c. Drawing C
d. Drawing D
e. Drawing E
____ 13. Which drawing depicts an atom with a valence of 3?
a. Drawing A
b. Drawing B
c. Drawing C
d. Drawing D
e. Drawing E
Use the information extracted from the periodic table in the figure below to answer the following questions.
____ 14. How many electrons would be expected in the outermost electron shell of an atom with atomic number 12?
a. 1
b. 2
c. 4
d. 6
e. 8
____ 15. Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom?
a. 1
b. 3
c. 5
d. 7
e. 9
____ 16. What do atoms form when they share electron pairs?
a. elements
b. ions
c. aggregates
d. isotopes
e. molecules
____ 17. What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen?
a. 1
b. 2
c. 3
d. 4
e. 6
____ 18. What do the four elements most abundant in life-carbon, oxygen, hydrogen, and nitrogen-have in common?
a. They all have the same number of valence electrons.
b. Each element exists in only one isotopic form.
c. They are equal in electronegativity.
d. They are elements produced only by living cells.
e. They all have unpaired electrons in their valence shells.
____ 19. When two atoms are equally electronegative, they will interact to form
a. equal numbers of isotopes.
b. ions.
c. polar covalent bonds.
d. nonpolar covalent bonds.
e. ionic bonds.
____ 20. A covalent bond is likely to be polar when
a. one of the atoms sharing electrons is much more electronegative than the other atom.
b. the two atoms sharing electrons are equally electronegative.
c. the two atoms sharing electrons are of the same element.
d. it is between two atoms that are both very strong electron acceptors.
e. the two atoms sharing electrons are different elements.
____ 21. What kind of a bond does NH4+ form with Cl- to make ammonium chloride salt (NH4Cl)?
a. nonpolar covalent
b. polar covalent
c. ionic
d. hydrogen
e. C and D only
____ 22. In ammonium chloride salt (NH4Cl) the anion is a single chloride ion, . What is the cation of NH4Cl?
a. N, with a charge of +3
b. H, with a charge of +1
c. H2 with a charge of +4
d. NH4 with a charge of +1
e. NH4 with a charge of +4
____ 23. A van der Waals interaction is the weak attraction between
a. the electrons of one molecule and the electrons of a nearby molecule.
b. the nucleus of one molecule and the electrons of a nearby molecule.
c. a polar molecule and a nearby nonpolar molecule.
d. a polar molecule and a nearby molecule that is also polar.
e. a nonpolar molecule and a nearby molecule that is also nonpolar.
____ 24. Which of the following is not considered to be a weak molecular interaction?
a. a covalent bond
b. a van der Waals interaction
c. an ionic bond in the presence of water
d. a hydrogen bond
e. A and B only
____ 25. Which of the following best describes chemical equilibrium?
a. Forward and reverse reactions continue with no effect on the concentrations of the reactants and products.
b. Concentrations of products are higher than the concentrations of the reactants.
c. Forward and reverse reactions have stopped so that the concentration of the reactants equals the concentration of the products.
d. Reactions stop only when all reactants have been converted to products.
e. There are equal concentrations of reactants and products, and the reactions have stopped.
____ 26. In a single molecule of water, the two hydrogen atoms are bonded to a single oxygen atom by
a. hydrogen bonds.
b. nonpolar covalent bonds.
c. polar covalent bonds.
d. ionic bonds.
e. van der Waals interactions.
____ 27. An example of a hydrogen bond is the bond between
a. C and H in methane (CH4).
b. the H of one water molecule and the O of another water molecule.
c. Na+and Cl- in salt.
d. the two hydrogen atoms in a molecule of hydrogen gas (H2).
e. Mg+and Cl- in MgCl2.
____ 28. Which of the following is a correct definition of a kilocalorie?
a. the amount of heat required to raise the temperature of 1 g of water by 1°F
b. the amount of heat required to raise the temperature of 1 g of water by 1°C
c. the amount of heat required to raise the temperature of 1 kg of water by 1°F
d. the amount of heat required to raise the temperature of 1 kg of water by 1°C
e. the amount of heat required to raise the temperature of 1,000 g of water by 1°F
____ 29. The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius?
a. 0.2°C
b. 1.0°C
c. 2.0°C
d. 10.0°C
e. 20.0°C
____ 30. Which bonds must be broken for water to vaporize?
a. ionic bonds
b. nonpolar covalent bonds
c. polar covalent bonds
d. hydrogen bonds
e. covalent bonds
____ 31. Desert rabbits are adapted to the warm climate because their large ears aid in the removal of heat due to the
a. high surface tension of water.
b. high heat of vaporization of water.
c. high specific heat of water.
d. buffering capacity of water.
e. dissociation of water molecules.
____ 32. Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon?
a. the change in density when it condenses to form a liquid or solid
b. reactions with other atmospheric compounds
c. the release of heat by the formation of hydrogen bonds
d. the release of heat by the breaking of hydrogen bonds
e. the high surface tension of water
____ 33. Why does ice float in liquid water?
a. The liquid water molecules have more kinetic energy and thus support the ice.
b. The ionic bonds between the molecules in ice prevent the ice from sinking.
c. Ice always has air bubbles that keep it afloat.
d. Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
e. The crystalline lattice of ice causes it to be denser than liquid water.
The picture below illustrates a solute molecule surrounded by a hydration shell of water. Use it to answer the following question.
____ 34. Based on your knowledge of the polarity of water molecules, the solute molecule is most likely
a. positively charged.
b. negatively charged.
c. without charge.
d. hydrophobic.
e. nonpolar.
____ 35. Hydrophobic substances such as vegetable oil are
a. nonpolar substances that repel water molecules.
b. nonpolar substances that have an attraction for water molecules.
c. polar substances that repel water molecules.
d. polar substances that have an affinity for water.
e. charged molecules that hydrogen-bond with water molecules.
____ 36. How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose?
a. 24
b. 342
c. 23 1014
d. 180 1014
e. 6.02 1023
____ 37. How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution?
a. 1
b. 14
c. 92
d. 1 107
e. 6.02 1023
Use the figure below to answer the following questions:
____ 38. How many grams of the molecule in the figure above would be equal to 1 mol of the molecule?
(Carbon = 12, Oxygen = 16, Hydrogen = 1)
a. 29
b. 30
c. 60
d. 150
e. 342
____ 39. Which of the following ionizes completely in solution and is considered to be a strong base?
a. NaCl
b. HCl
c. NH3
d. H2CO3
e. NaOH
____ 40. Which of the following solutions has the greatest concentration of hydrogen ions [H+]?
a. gastric juice at pH 2
b. vinegar at pH 3
c. tomato juice at pH 4
d. black coffee at pH 5
e. household bleach at pH 12
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