Chemistry Exam
Revision Questions & Answers
1. Which correctly describes the structure of an atom?
A. There are always the same number of protons and neutrons.
B. There are always the same number of protons and electrons.
C. There are always the same number of neutrons and electrons.
D. The number of protons, neutrons, and electrons is always the same
E. There are never the same number of neutrons and protons.
2. What directly determines an atom's identity?
A. the number of electrons
B. the number of neutrons
C. the number of protons
D. the number of bonds it can form
E. the ratio of protons to electrons
3. Carbon12 and carbon14 are isotopes. How are they different from each other?
A. different numbers of protons
B. different numbers of neutrons
C. different numbers of electrons
D. they can form different numbers of chemical bonds
E. different number of energy shells
4. Which is a covalent bond?
A. two atoms share inner orbit electrons with each other
B. a bond between water molecules
C. a bond between two oppositely charged ions
D. a bond between two free radicals
,E. two atoms share outer orbit electrons with each other
5. Ions are
A. electrically neutral.
B. electrically charged.
C. formed by the gain or loss of protons from the nucleus.
D. insoluble in water.
E. nonpolar atoms.
6. When magnesium loses electrons to become an ion, what does it become?
A. a covalent molecule
B. a cation
C. an anion
D. a new element
E. a free radical
7. If a sports beverage advertises that it replaces the body's electrolytes, what does the drink
contain?
A. sugars that were broken down for energy
B. ionic forms of mineral elements
C. lipids that form the membranes of cells
D. oxygen and gases used by metabolism
E. vitamins
8. Of these major ions found in the body, which one carries a negative charge?
A. Chloride
B. Sodium
C. Potassium
D. Hydrogen
, E. Calcium
9. Which describes a characteristic of free radicals?
A. They rapidly oxidize other atoms by removing an electron.
B. They are inert molecules that don't interact readily with other molecules.
C. They contain two electrons in the outermost orbital.
D. They have extra neutrons in their nuclei.
E. They are found in high quantities in most sports drinks.
10. Which is true about electrolytes?
A. They are neutral atoms.
B. They conduct electricity when dissolved in water.
C. They are found in pure water.
D. They have equal numbers of protons and electrons.
E. They are insoluble in water.
11. Which of the following is not true of a polar chemical bond?
A. It is covalent
B. It is ionized
C. It has opposite electrical charge at each end
D. It has no net electrical charge
12. Which best describes a hydrolysis reaction?
A. Molecules are broken down into smaller ones by breaking covalent bonds within water molecules
and transferring hydrogen atoms and hydroxyl groups to the smaller ones.
B. Electrically charged molecules separate into ions when they dissolve in water, and then hydrogen
ions and hydroxyl groups covalently attach themselves to the oppositely charged ions.
C. Large molecules are assembled from smaller ones by breaking water into hydrogen and hydroxylions.
D. Dissolving a large molecule in water reduces it to its individual atoms.
Revision Questions & Answers
1. Which correctly describes the structure of an atom?
A. There are always the same number of protons and neutrons.
B. There are always the same number of protons and electrons.
C. There are always the same number of neutrons and electrons.
D. The number of protons, neutrons, and electrons is always the same
E. There are never the same number of neutrons and protons.
2. What directly determines an atom's identity?
A. the number of electrons
B. the number of neutrons
C. the number of protons
D. the number of bonds it can form
E. the ratio of protons to electrons
3. Carbon12 and carbon14 are isotopes. How are they different from each other?
A. different numbers of protons
B. different numbers of neutrons
C. different numbers of electrons
D. they can form different numbers of chemical bonds
E. different number of energy shells
4. Which is a covalent bond?
A. two atoms share inner orbit electrons with each other
B. a bond between water molecules
C. a bond between two oppositely charged ions
D. a bond between two free radicals
,E. two atoms share outer orbit electrons with each other
5. Ions are
A. electrically neutral.
B. electrically charged.
C. formed by the gain or loss of protons from the nucleus.
D. insoluble in water.
E. nonpolar atoms.
6. When magnesium loses electrons to become an ion, what does it become?
A. a covalent molecule
B. a cation
C. an anion
D. a new element
E. a free radical
7. If a sports beverage advertises that it replaces the body's electrolytes, what does the drink
contain?
A. sugars that were broken down for energy
B. ionic forms of mineral elements
C. lipids that form the membranes of cells
D. oxygen and gases used by metabolism
E. vitamins
8. Of these major ions found in the body, which one carries a negative charge?
A. Chloride
B. Sodium
C. Potassium
D. Hydrogen
, E. Calcium
9. Which describes a characteristic of free radicals?
A. They rapidly oxidize other atoms by removing an electron.
B. They are inert molecules that don't interact readily with other molecules.
C. They contain two electrons in the outermost orbital.
D. They have extra neutrons in their nuclei.
E. They are found in high quantities in most sports drinks.
10. Which is true about electrolytes?
A. They are neutral atoms.
B. They conduct electricity when dissolved in water.
C. They are found in pure water.
D. They have equal numbers of protons and electrons.
E. They are insoluble in water.
11. Which of the following is not true of a polar chemical bond?
A. It is covalent
B. It is ionized
C. It has opposite electrical charge at each end
D. It has no net electrical charge
12. Which best describes a hydrolysis reaction?
A. Molecules are broken down into smaller ones by breaking covalent bonds within water molecules
and transferring hydrogen atoms and hydroxyl groups to the smaller ones.
B. Electrically charged molecules separate into ions when they dissolve in water, and then hydrogen
ions and hydroxyl groups covalently attach themselves to the oppositely charged ions.
C. Large molecules are assembled from smaller ones by breaking water into hydrogen and hydroxylions.
D. Dissolving a large molecule in water reduces it to its individual atoms.
