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

Question 1

Which of the following best describes the difference between mass and weight?

Accepted Answer

Mass is the amount of matter in an object, while weight is the force exerted by gravity on that mass.

Question 2

Which element makes up the largest percentage of body mass in humans, according to Table 2.1?

Accepted Answer

Oxygen

Question 3

A compound has emergent properties that are different from its constituent elements. Which real-world example best illustrates this concept?

Accepted Answer

Sodium chloride (NaCl) is formed from sodium (a reactive metal) and chlorine (a toxic gas), but NaCl is a stable, edible salt.

Question 4

What is the atomic mass of sodium ($$	ext{Na}) $$given that it has 11 protons and 12 neutrons?

Accepted Answer

$$23$$

Question 5

Which of the following statements about electron shells is correct?

Accepted Answer

Electrons in the outermost shell (valence shell) determine the chemical behavior of an atom.

Question 6

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number $$= 8$$, mass number $$= 16$$

Question 7

Which of the following best explains why noble gases are chemically inert?

Accepted Answer

They have a full valence shell of electrons.

Question 8

What is the main difference between a covalent bond and an ionic bond?

Accepted Answer

Covalent bonds involve sharing electrons, while ionic bonds involve transferring electrons.

Question 9

Which equation represents the photosynthesis reaction?

Accepted Answer

$$6	ext{CO}_2 + 6	ext{H}_2	ext{O} ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6	ext{O}_2$$

Question 10

Which of the following is a trace element required by humans in minute quantities?

Accepted Answer

Zinc (Zn)

Question 11

A hydrogen bond is most likely to form between which atoms in living cells?

Accepted Answer

A hydrogen atom covalently bonded to oxygen or nitrogen, attracted to another oxygen or nitrogen atom.

Question 12

Which of the following best describes chemical equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate, and the concentrations of reactants and products remain constant.

Question 13

Which statement about van der Waals interactions is correct?

Accepted Answer

They are weak attractions that occur when electrons are unevenly distributed in molecules.

Question 14

Which of the following is NOT a type of chemical bond found in biological molecules?

Accepted Answer

Metallic bond

Question 15

What is the charge of a sodium ion ($$	ext{Na}^+) $$after it loses one electron?

Accepted Answer

$$+1$$

Question 16

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in partial charges on the atoms.

Question 17

Which element is most likely to form a cation in an ionic bond?

Accepted Answer

Sodium (Na)

Question 18

If a molecule consists of two hydrogen atoms sharing electrons, what type of bond is formed?

Accepted Answer

Single covalent bond

Question 19

Which of the following is a real-life example of a weak chemical interaction that is biologically important?

Accepted Answer

The adhesion of a gecko’s toe hairs to a wall surface via van der Waals interactions.

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

Study Guide - Practice Questions