Question 1

Which four elements make up approximately 96% of the human body's mass?

Accepted Answer

Carbon, hydrogen, nitrogen, oxygen

Question 2

What is the most important determinant of an atom's bonding behavior?

Accepted Answer

The number of valence electrons

Question 3

Which type of chemical bond involves the sharing of electron pairs between atoms?

Accepted Answer

Covalent bond

Question 4

In a polar covalent bond, which atom will have a negative charge?

Accepted Answer

The atom that carries the shared electron more of the time

Question 5

Which property of water allows it to moderate Earth's temperature?

Accepted Answer

High specific heat capacity

Question 6

Which equation correctly represents the process of photosynthesis?

Accepted Answer

$$6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2$$

Question 7

Which emergent property of water is most directly responsible for the ability of insects to walk on water?

Accepted Answer

Cohesive/adhesive behavior

Question 8

Which statement best describes an ionic bond?

Accepted Answer

It forms when one atom donates an electron to another atom, creating oppositely charged ions that attract each other.

Question 9

Why are hydrogen bonds important for the properties of water?

Accepted Answer

They allow water molecules to stick together, giving water high cohesion and surface tension.

Question 10

Which of the following best explains why carbon dioxide ($$\mathrm{CO}_2) is a $$nonpolar molecule?

Accepted Answer

It has a linear and symmetrical structure, resulting in equal sharing of electrons.

Question 11

Which of the following is a trace element required for thyroid gland metabolism?

Accepted Answer

Iodine

Question 12

Which type of chemical reaction is represented by the equation $$\mathrm{AB} + \mathrm{CD} \rightarrow \mathrm{AC} + \mathrm{BD}$$?

Accepted Answer

Exchange reaction

Question 13

What is the main reason water is considered a universal solvent?

Accepted Answer

Its polarity allows it to dissolve many ionic and polar substances.

Question 14

Which of the following best describes a radioactive isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons, and an unstable nucleus that decays over time.

Question 15

Which of the following is NOT an emergent property of water that supports life?

Accepted Answer

High viscosity

Question 16

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

Accepted Answer

Ice is less dense than liquid water due to hydrogen bonds forming a lattice structure.

Question 17

Which of the following chemical reactions releases energy?

Accepted Answer

Breaking bonds in reactants to form products with lower energy

Question 18

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak electrical attraction between a hydrogen atom in a polar molecule and an oxygen or nitrogen atom in another molecule

Question 19

Which of the following scenarios best illustrates the biological significance of water's high specific heat?

Accepted Answer

Coastal regions experience milder temperatures compared to inland areas due to water absorbing and releasing heat slowly.

Question 20

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

Accepted Answer

The electrons are shared unequally, resulting in a polar molecule.

Chemistry of Life: Atoms, Bonds, and Water in Biology

Study Guide - Practice Questions