Question 1

Which of the following statements best describes the difference between a molecule and a compound?

Accepted Answer

A molecule is two or more atoms chemically combined, while a compound is two or more different elements chemically combined.

Question 2

Which of the following elements makes up the largest percentage of the human body by mass?

Accepted Answer

Oxygen

Question 3

A sodium atom (Na) loses one electron to become a sodium ion (Na⁺). What type of ion is formed and why?

Accepted Answer

A cation, because it loses a negative charge.

Question 4

Which of the following best explains why water is considered a polar molecule?

Accepted Answer

The oxygen atom attracts electrons more strongly, creating a partial negative charge near oxygen and a partial positive charge near hydrogen.

Question 5

Which of the following is a correct representation of a synthesis (anabolic) reaction?

Accepted Answer

$$A + B \rightarrow AB$$

Question 6

A solution has a pH of 4. Which of the following statements is true about this solution?

Accepted Answer

It is acidic and has a high concentration of hydrogen ions.

Question 7

Which of the following best describes the role of buffers in the human body?

Accepted Answer

Buffers maintain a stable pH by neutralizing excess acids or bases.

Question 8

Which of the following is NOT a property of water that makes it vital to life?

Accepted Answer

It is a nonpolar molecule.

Question 9

Which of the following best describes dehydration synthesis?

Accepted Answer

Monomers are joined to form polymers by removing water.

Question 10

A patient is given intravenous fluids containing sodium and potassium ions. Why are these ions important for body function?

Accepted Answer

They are essential for nerve impulse transmission.

Question 11

Which of the following best describes the difference between an ionic bond and a covalent bond?

Accepted Answer

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

Question 12

Which of the following is a trace element in the human body and is required for enzyme activation?

Accepted Answer

Zinc

Question 13

Which of the following organic molecules is correctly matched with its building block?

Accepted Answer

Carbohydrates – monosaccharides

Question 14

Which of the following best describes ATP’s role in the cell?

Accepted Answer

ATP is the main energy currency used by cells.

Question 15

A molecule of glucose (C$$_6H$_{12}O$_6) is $$classified as which type of carbohydrate?

Accepted Answer

Monosaccharide

Question 16

Which of the following best explains why phospholipids are important in cell membranes?

Accepted Answer

Their hydrophobic tails and hydrophilic heads allow them to form a bilayer that separates the cell from its environment.

Question 17

Which of the following is true about the rule of eights (octet rule) in chemical bonding?

Accepted Answer

Atoms are most stable when their outermost shell contains 8 electrons.

Question 18

Which of the following best describes a catabolic (decomposition) reaction in the body?

Accepted Answer

$$AB \rightarrow A + B$$

Question 19

Which of the following is a property of acids?

Accepted Answer

They release hydrogen ions (H$$^+) in $$solution.

Question 20

Which of the following best describes the process of hydrolysis?

Accepted Answer

Polymers are broken down into monomers by adding water.

Chapter 2: Basic Chemistry – Essentials of Human Anatomy & Physiology

Study Guide - Practice Questions