Question 1

Which of the following elements is the most abundant in the human body by mass?

Accepted Answer

Oxygen (O)

Question 2

What is the atomic number of an element, and how is it determined?

Accepted Answer

The number of protons in the nucleus

Question 3

Which of the following best describes an isotope?

Accepted Answer

Atoms with the same number of protons but different numbers of neutrons

Question 4

If an atom has 11 protons, 12 neutrons, and 11 electrons, what is its atomic mass?

Accepted Answer

$$23$$

Question 5

Which shell has the highest potential energy for electrons in an atom?

Accepted Answer

The outermost shell

Question 6

What is the maximum number of electrons that can be held in the second shell of an atom?

Accepted Answer

$$8$$

Question 7

Which of the following molecules is nonpolar?

Accepted Answer

Methane ($$\mathrm{CH_4$})$$

Question 8

What determines whether a covalent bond is polar or nonpolar?

Accepted Answer

The difference in electronegativity between the atoms

Question 9

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed when one atom donates an electron to another atom

Question 10

Which of the following is true about hydrogen bonds?

Accepted Answer

They require a partially positive hydrogen and a partially negative atom (O, N, or F)

Question 11

Which of the following is an example of a reversible chemical reaction?

Accepted Answer

$$\mathrm{CO_2$ + H_2O \rightleftharpoons H_2CO_3}$$

Question 12

Which of the following statements about van der Waals interactions is correct?

Accepted Answer

They are weak forces that can occur between any two atoms due to temporary charge fluctuations

Question 13

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

Accepted Answer

Oxygen is more electronegative than hydrogen, creating a partial negative charge on oxygen

Question 14

What is the main reason atoms form chemical bonds?

Accepted Answer

To achieve a full valence shell of electrons

Question 15

Which of the following is true about covalent bonds?

Accepted Answer

They involve the sharing of electrons between atoms

Question 16

Which of the following molecules would you expect to have the highest number of hydrogen bonds with water?

Accepted Answer

Ammonia ($$\mathrm{NH_3$})$$

Question 17

Which of the following is a correct statement about the periodic table?

Accepted Answer

Elements are arranged by increasing atomic number

Question 18

Which of the following best describes a polypeptide?

Accepted Answer

A chain of amino acids linked by covalent bonds

Question 19

Which of the following is true about electrons in an atom?

Accepted Answer

Electrons are found in shells around the nucleus

Question 20

Which of the following is a product of photosynthesis?

Accepted Answer

Glucose ($$\mathrm{C_6H_{12}O_6$})$$

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

Study Guide - Practice Questions