Question 1

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 2

What is the mass number of an atom with 6 protons, 6 neutrons, and 6 electrons?

Accepted Answer

$$12$$

Question 3

Which type of chemical bond involves the transfer of electrons from one atom to another?

Accepted Answer

Ionic bond

Question 4

Why is water considered an excellent solvent for biological molecules?

Accepted Answer

Its polar nature allows it to interact with and dissolve other polar molecules and ions.

Question 5

Which property of water allows trees to transport water from roots to leaves?

Accepted Answer

Cohesion and adhesion

Question 6

What is the main difference between isotopes of the same element?

Accepted Answer

Number of neutrons

Question 7

Which equation correctly represents the ionization of water?

Accepted Answer

$$H_2O \rightarrow H^+ + OH^-$$

Question 8

A solution with a pH of 3 has a hydrogen ion concentration of:

Accepted Answer

$$10^{-3}$$ moles/liter

Question 9

Which of the following best explains why ice floats on water?

Accepted Answer

Hydrogen bonds in ice cause molecules to spread farther apart, making ice less dense.

Question 10

Which type of bond is responsible for the unique properties of water, such as cohesion and high specific heat?

Accepted Answer

Hydrogen bonds

Question 11

If an atom has a partially full outermost electron shell, what is most likely to happen?

Accepted Answer

It will form chemical bonds with other atoms to fill its shell.

Question 12

Which of the following is a trace element essential for thyroid hormone production?

Accepted Answer

Iodine

Question 13

What happens when an acid is added to water?

Accepted Answer

The concentration of $$H^+$$ increases.

Question 14

Which of the following molecules is hydrophobic and will not dissolve in water?

Accepted Answer

Oil

Question 15

A buffer in a biological system functions to:

Accepted Answer

Maintain a constant pH by accepting or releasing $$H^+$$ ions.

Question 16

Which of the following is true about covalent bonds in biological molecules?

Accepted Answer

They involve the sharing of electrons between atoms.

Question 17

What is the result of water's high heat of vaporization for living organisms?

Accepted Answer

It allows sweat to absorb excess body heat, cooling the organism.

Question 18

Which of the following best describes a free radical?

Accepted Answer

An atom with a partially full outer shell that is highly reactive and can damage other molecules.

Question 19

Which of the following is a real-world example of a radioactive isotope used in medicine?

Accepted Answer

Iodine-131 for thyroid imaging

Question 20

Which of the following best explains the role of buffers in blood?

Accepted Answer

Buffers maintain blood pH by accepting or releasing $$H^+$$ ions in response to changes.

Atoms, Molecules, and Life: Foundations of Biological Chemistry

Study Guide - Practice Questions