Sodium becomes a cation ($$\text{Na}^+) $$and chlorine becomes an anion ($$\text{Cl}^-$$), forming an ionic bond.

Carbon dioxide ($$\text{CO}_2)$$

$$\text{Mass number} = \text{Number of protons} + \text{Number of neutrons}$$

$$\text{Atomic number} = \text{Number of protons}$$

Question 1

Which of the following best describes the difference between the planetary and orbital models of the atom, as shown in the first image?

Accepted Answer

The planetary model shows electrons in fixed circular paths, while the orbital model depicts probable regions of electron density.

Question 2

Based on the second image, which atom has the greatest number of protons in its nucleus?

Accepted Answer

Lithium

Question 3

Referencing the third image, which isotope of hydrogen contains two neutrons?

Accepted Answer

Tritium ($$^3	ext{H})$$

Question 4

In the fourth image, which element has a valence shell with only one electron, making it highly reactive?

Accepted Answer

Hydrogen

Question 5

Using the fifth image, what happens when sodium (Na) transfers an electron to chlorine (Cl)?

Accepted Answer

Sodium becomes a cation ($$	ext{Na}^+) $$and chlorine becomes an anion ($$	ext{Cl}^-$$), forming an ionic bond.

Question 6

The sixth image shows a crystal lattice structure. What type of compound forms this structure?

Accepted Answer

Ionic compound (salt)

Question 7

In the seventh image, two oxygen atoms are shown sharing two pairs of electrons. What type of bond is formed?

Accepted Answer

Double covalent bond

Question 8

The eighth image illustrates two nitrogen atoms sharing three pairs of electrons. Which formula represents this molecule?

Accepted Answer

$$	ext{N}_2$$

Question 9

In the ninth image, the linear and symmetrical shape of the molecule indicates it is nonpolar. Which molecule is depicted?

Accepted Answer

Carbon dioxide ($$	ext{CO}_2)$$

Question 10

The tenth image shows a V-shaped molecule with partial charges. What property does this shape and charge distribution confer to water?

Accepted Answer

Polarity, making water a dipole

Question 11

Based on the eleventh image, which bond type involves a complete transfer of electrons?

Accepted Answer

Ionic bond

Question 12

The twelfth image shows dotted lines between water molecules. What is the significance of these dotted lines?

Accepted Answer

They represent hydrogen bonds, which are responsible for water's high surface tension.

Question 13

In the thirteenth image, a water strider is able to walk on water. Which property of water allows this phenomenon?

Accepted Answer

High surface tension due to hydrogen bonding

Question 14

Which equation correctly represents the mass number of an atom?

Accepted Answer

$$	ext{Mass number} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Question 15

Which equation describes the atomic number of an element?

Accepted Answer

$$	ext{Atomic number} = 	ext{Number of protons}$$

Question 16

A patient is injected with a radioisotope for diagnostic imaging. Which property of radioisotopes makes them useful for this purpose?

Accepted Answer

They emit detectable radiation as they decay to more stable forms.

Question 17

Which of the following statements about trace elements in the human body is correct?

Accepted Answer

Trace elements are present in very minute amounts and often activate enzymes.

Question 18

Which of the following is a real-world example of a polar covalent bond?

Accepted Answer

The bond between oxygen and hydrogen in water ($$	ext{H}_2	ext{O})$$

Question 19

Which of the following best explains why noble gases are chemically inert?

Accepted Answer

Their valence shell is fully occupied with electrons, making them stable.

Chemistry Comes Alive: Structure and Properties of Matter

Study Guide - Practice Questions