Question 1

Atoms have no electric charge because they have ________.

Accepted Answer

A)  uncharged neutrons in their nuclei 
B)  an equal number of protons and neutrons 
C)  an equal number of protons and electrons 
D)  an equal number of charged and uncharged subatomic particles

Question 2

Which of the following atoms has the smallest number of neutrons?

Accepted Answer

A)  nitrogen-14 
B)  carbon-14 
C)  oxygen-16 
D)  neon-20

Question 3

A neutral atom has 2, 8, 8 electrons in its first, second, and third energy levels. This information ________.

Accepted Answer

A)  does not tell us about the atomic number of the element 
B)  does not tell us about the chemical properties of the element 
C)  does not tell us about the atomic mass of the element 
D)  does not tell us about the size of the element

Question 4

If an atom has a charge of +1, which of the following must be true?

Accepted Answer

A)  It has two more protons than neutrons. 
B)  It has the same number of protons as electrons. 
C)  It has one more electron than it does protons. 
D)  It has one more proton than it does electrons.

Question 5

In the term trace element, the adjective trace means that ________.

Accepted Answer

A)  the element is required in very small amounts 
B)  the element can be used as a label to trace atoms through an organism's metabolism 
C)  the element is very rare on Earth 
D)  the element enhances health but is not essential for the organism's long-term survival

Question 6

Based on electron configuration, which of the elements would exhibit a chemical behavior similar to oxygen?

Accepted Answer

A)  carbon 
B)  nitrogen 
C)  sulfur 
D)  phosphorus

Question 7

Considering that the reactants have no charge, what are the products of the reaction shown above?

Accepted Answer

A)  a cation with a net charge of +1 and an anion with a net charge of +1 
B)  a cation with a net charge of -1 and an anion with a net charge of -1 
C)  a cation with a net charge of -1 and an anion with a net charge of +1 
D)  a cation with a net charge of +1 and an anion with a net charge of -1

Question 8

Elements 72Zn, 75As, and 74Ge have the same number of ________.

Accepted Answer

A)  protons 
B)  protons and electrons 
C)  neutrons 
D)  neutrons and electrons

Question 9

Nitrogen (N) normally forms three covalent bonds with a valence of five. However, ammonium has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of one). What do you predict to be the charge on ammonium?

Accepted Answer

A)  +1 
B)  -1 
C)  +2 
D)  -2

Question 10

Elements found in the first two columns of the periodic table contain outer electron shells that are ________; these elements tend to form ________ in solution.

Accepted Answer

A)  almost empty; cations 
B)  almost empty; anions 
C)  almost full; cations 
D)  almost full; anions

Question 11

How many electrons will a single atom of nitrogen with no charge and no bonds have in its valence shell?

Accepted Answer

A)  2 
B)  5 
C)  7 
D)  14

Question 12

How is a covalent bond formed?

Accepted Answer

A)  two atoms share two pairs of electrons 
B)  two atoms share two electrons 
C)  two atoms share one electron 
D)  one atom loses a pair of electrons to the other

Question 13

The atomic number of nitrogen is 7. Which of the following explains the greater mass number of nitrogen-15 compared to nitrogen-14? Nitrogen-15 contains ________.

Accepted Answer

A)  7 neutrons and nitrogen-14 contains 8 neutrons 
B)  8 neutrons and nitrogen-14 contains 7 neutrons 
C)  8 protons and nitrogen 14 contains 7 protons 
D)  15 protons and nitrogen-14 contains 14 protons

Question 14

To find out the number of neutrons in an atom, we need to know the following.

Accepted Answer

A)  atomic number 
B)  electron number 
C)  mass number 
D)  mass and atomic number

Question 15

In the above diagram, what kind of bond is most likely to form between V and Z?

Accepted Answer

A)  ionic 
B)  covalent 
C)  hydrogen 
D)  van der Waals

Question 16

The atomic number of chlorine is 17. The atomic number of magnesium is 12. Given this information, what is the formula for magnesium chloride?

Accepted Answer

A)  MgCl 
B)  MgCl2 
C)  Mg2Cl 
D)  MgCl3

Question 17

Which of the following types of bond is broken when water evaporates?

Accepted Answer

A)  nonpolar covalent bonds 
B)  ionic bonds 
C)  hydrogen bonds 
D)  polar covalent bonds

Question 18

How many electrons participate in a triple covalent bond?

Accepted Answer

A)  3 
B)  6 
C)  9 
D)  12

Question 19

Which pair of elements in the diagram is most likely to form a covalent bond?

Accepted Answer

A)  V and Z 
B)  V and Y 
C)  V and X 
D)  W and Z

Question 20

What is the atomic number of the neutral atom represented by the Periodic Table block in the figure?

Accepted Answer

A)  18 
B)  19 
C)  22 
D)  39

Exam 2: Atoms and Molecules