$$\text{Atomic mass} = \text{Number of protons} + \text{Number of neutrons}$$

Question 1

Which statement best describes a compound?

Accepted Answer

A substance composed of two or more elements in a fixed ratio

Question 2

Which four elements make up approximately 96% of living matter?

Accepted Answer

C, N, O, and H

Question 3

What is the atomic number of an element?

Accepted Answer

The number of protons in the nucleus

Question 4

Given a sodium atom with atomic number 11 and mass number 23, how many neutrons does it have?

Accepted Answer

12

Question 5

Which subatomic particle is responsible for the chemical reactivity of an atom?

Accepted Answer

Electron

Question 6

If an atom has 6 protons, 6 neutrons, and 6 electrons, what is its atomic mass?

Accepted Answer

$$12$$

Question 7

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 8

What type of bond is formed when electrons are shared equally between two atoms?

Accepted Answer

Nonpolar covalent bond

Question 9

Which element is considered a trace element essential for vertebrates?

Accepted Answer

Iodine

Question 10

What is the charge of a fluoride ion with 9 protons, 10 neutrons, and 10 electrons?

Accepted Answer

$$-1$$

Question 11

Which of the following molecules contains a nonpolar covalent bond?

Accepted Answer

CH$$_4$$

Question 12

What is the main reason why atoms form chemical bonds?

Accepted Answer

To fill their valence shell and achieve stability

Question 13

Which type of bond is responsible for the attraction between water molecules?

Accepted Answer

Hydrogen bond

Question 14

What is the mass number of a lithium atom with 3 protons and 4 neutrons?

Accepted Answer

$$7$$

Question 15

Which of the following is true about van der Waals interactions?

Accepted Answer

They result from shifting positive and negative areas due to moving electrons

Question 16

Which process is used to determine the age of fossils by measuring isotope ratios?

Accepted Answer

Radiometric dating

Question 17

If an atom has a full valence shell, what is its reactivity?

Accepted Answer

Stable and nonreactive

Question 18

Which of the following best explains why water is a polar molecule?

Accepted Answer

Oxygen is more electronegative, creating partial charges

Question 19

What is the formula for calculating the atomic mass of an atom?

Accepted Answer

$$	ext{Atomic mass} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Question 20

Which of the following is a real-world consequence of trace element deficiency in humans?

Accepted Answer

Goiter due to iodine deficiency

The Chemical Context of Life: Elements, Atoms, and Matter

Study Guide - Practice Questions