Question 1

Which of the following best describes the difference between an atomic number and an atomic mass?

Accepted Answer

Atomic number is the number of protons in an atom, while atomic mass is the sum of protons and neutrons.

Question 2

A sodium atom ($\mathrm{Na}$) has 11 protons, 12 neutrons, and 11 electrons. What is its atomic mass?

Accepted Answer

$23$

Question 3

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 4

Which of the following best describes a covalent bond?

Accepted Answer

Electrons are shared between atoms.

Question 5

What does the term 'electronegativity' refer to in the context of chemical bonding?

Accepted Answer

The ability of an atom to attract electrons in a chemical bond.

Question 6

Which of the following is true about hydrogen bonds?

Accepted Answer

Hydrogen bonds occur between molecules, not within them.

Question 7

A solution has a $[\mathrm{H}^+]$ concentration of $1 	imes 10^{-4}$ M. What is its pH?

Accepted Answer

$4$

Question 8

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

Accepted Answer

It has a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom.

Question 9

When sodium chloride ($\mathrm{NaCl}$) dissolves in water, what happens to the ions?

Accepted Answer

They dissociate into $\mathrm{Na}^+$ and $\mathrm{Cl}^-$ ions, which are surrounded by water molecules.

Question 10

Which of the following best describes the function of a buffer in biological systems?

Accepted Answer

A buffer resists changes in pH when acids or bases are added.

Question 11

Which of the following is an example of an anabolic reaction?

Accepted Answer

The synthesis of proteins from amino acids.

Question 12

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes are proteins that speed up chemical reactions by lowering the activation energy.

Question 13

Which of the following best describes the difference between endergonic and exergonic reactions?

Accepted Answer

Endergonic reactions absorb energy, while exergonic reactions release energy.

Question 14

Which of the following is the general chemical formula for carbohydrates?

Accepted Answer

$\mathrm{C}_n\mathrm{H}_{2n}\mathrm{O}_n$

Question 15

Which of the following is a monomer of proteins?

Accepted Answer

Amino acid

Question 16

What is the primary difference between DNA and RNA?

Accepted Answer

DNA is double-stranded, while RNA is single-stranded.

Question 17

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water's polarity allows it to surround and separate ions.

Question 18

Which of the following best describes the process of hydrolysis?

Accepted Answer

The breakdown of a molecule by adding water.

Question 19

A patient is experiencing acidosis. Which of the following best describes their blood pH?

Accepted Answer

Their blood pH is below 7.35.

Question 20

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP provides energy for cellular processes by releasing a phosphate group.

Chapter 2 Study Guide: Atoms, Chemical Bonds, Water, and Biological Macromolecules

Study Guide - Practice Questions