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

Question 1

Which four elements make up approximately 96% of an organism's body mass?

Accepted Answer

Carbon, Hydrogen, Nitrogen, Oxygen

Question 2

Which statement best describes a compound?

Accepted Answer

A substance formed when two or more different elements combine in a fixed ratio

Question 3

What is the atomic mass of an atom with 6 protons and 7 neutrons?

Accepted Answer

$$6 + 7 = 13$$

Question 4

Which of the following is true about isotopes?

Accepted Answer

They have the same number of protons but different numbers of neutrons

Question 5

In a neutral atom, the number of electrons is equal to the number of:

Accepted Answer

Protons

Question 6

How many electrons can occupy the third energy level (shell) of an atom?

Accepted Answer

$$8$$

Question 7

Which type of bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Question 8

What determines the chemical properties and reactivity of an atom?

Accepted Answer

The number of electrons, especially valence electrons

Question 9

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally due to differences in electronegativity

Question 10

What is the result when an atom loses an electron?

Accepted Answer

It becomes a cation with a positive charge

Question 11

Which of the following is true about chemical reactions?

Accepted Answer

They involve making and breaking chemical bonds

Question 12

Which equation correctly represents the photosynthesis reaction?

Accepted Answer

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

Question 13

Which statement is correct regarding molecules and compounds?

Accepted Answer

All compounds are molecules, but not all molecules are compounds

Question 14

If an atom has 15 electrons, how are they distributed in its energy levels?

Accepted Answer

2 in the first, 8 in the second, 5 in the third

Question 15

Which of the following is a trace element required in very small amounts by organisms?

Accepted Answer

Iron

Question 16

What is the main difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons

Question 17

Which property of atoms determines their placement in the same column of the periodic table?

Accepted Answer

Number of valence electrons

Question 18

What happens at chemical equilibrium in a reversible reaction?

Accepted Answer

The rate of the forward reaction equals the rate of the reverse reaction

Question 19

Which of the following is NOT a characteristic of compounds?

Accepted Answer

Can be broken down by physical means

The Chemical Context of Life: Foundations of Biological Chemistry

Study Guide - Practice Questions