Question 1

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements that are chemically bonded together.

Question 2

Which of the following is a molecule, but NOT a compound?

Accepted Answer

$$\mathrm{O}_2$$

Question 3

What is the most abundant element in the human body by mass?

Accepted Answer

Oxygen

Question 4

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 5

An atom of carbon has 6 protons, 6 neutrons, and 6 electrons. What is its mass number?

Accepted Answer

$$12$$

Question 6

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from one atom to another.

Question 7

Which type of chemical reaction is represented by the equation $$\mathrm{AB} \rightarrow \mathrm{A} + \mathrm{B}$$?

Accepted Answer

Decomposition reaction

Question 8

If a solution has a pH of 3, which of the following statements is true?

Accepted Answer

It is acidic and has more hydrogen ions than a solution with pH 7.

Question 9

Which organic compound is the main source of energy for cells?

Accepted Answer

Carbohydrates

Question 10

Which of the following is the building block (monomer) of proteins?

Accepted Answer

Amino acids

Question 11

A DNA molecule contains the sequence $$\mathrm{ATCG}. $$What is the corresponding sequence on the complementary strand?

Accepted Answer

$$\mathrm{TAGC}$$

Question 12

How many electrons are in a neutral atom of oxygen ($$Z = 8$$)?

Accepted Answer

$$8$$

Question 13

Which of the following best explains why enzymes are important in biological systems?

Accepted Answer

They lower the activation energy required for chemical reactions.

Question 14

Which of the following is true about valence electrons?

Accepted Answer

They are involved in chemical bonding and are found in the outermost shell of an atom.

Question 15

A solution with a pH of 9 is considered:

Accepted Answer

Basic

Question 16

Which of the following is a correct statement about isotopes?

Accepted Answer

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

Question 17

Which of the following is a product of a synthesis reaction?

Accepted Answer

$$\mathrm{H}_2 + \mathrm{O}_2 \rightarrow \mathrm{H}_2\mathrm{O}$$

Question 18

Which of the following statements about water is correct?

Accepted Answer

Water is a polar molecule and an excellent solvent for ionic compounds.

Question 19

If the atomic number of chlorine is 17, how many valence electrons does it have?

Accepted Answer

$$7$$

Question 20

Which of the following best describes a buffer?

Accepted Answer

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

Fundamental Chemistry Concepts for Anatomy & Physiology

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