$$\text{Mass Number} = \text{Number of Protons} + \text{Number of Neutrons}$$

$$\text{Atomic Number} = \text{Number of Protons}$$

Question 1

Which of the following best describes an isotope?

Accepted Answer

Atoms with the same number of protons but different numbers of neutrons.

Question 2

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 has more protons than electrons.

Question 3

Which of the following equations correctly represents the calculation of the mass number of an atom?

Accepted Answer

$$	ext{Mass Number} = 	ext{Number of Protons} + 	ext{Number of Neutrons}$$

Question 4

Which property of water allows it to help regulate body temperature in humans?

Accepted Answer

High heat capacity

Question 5

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 6

Which of the following best describes a decomposition reaction?

Accepted Answer

A reaction that breaks a molecule into smaller fragments.

Question 7

A solution with a pH of 3 is considered:

Accepted Answer

Acidic, because it has a high concentration of hydrogen ions.

Question 8

Which of the following is a property of hydrophilic molecules?

Accepted Answer

They interact with water and dissolve easily.

Question 9

Which of the following best describes the structure of a water molecule?

Accepted Answer

Two hydrogen atoms covalently bonded to one oxygen atom, with an asymmetrical electron distribution.

Question 10

Which of the following is the correct formula for calculating the atomic number of an element?

Accepted Answer

$$	ext{Atomic Number} = 	ext{Number of Protons}$$

Question 11

Which of the following statements about organic molecules is correct?

Accepted Answer

They always contain carbon and hydrogen, and generally oxygen as well.

Question 12

Which of the following best describes a polysaccharide?

Accepted Answer

A carbohydrate formed by the bonding of many monosaccharide molecules.

Question 13

Which of the following is a function of proteins in the human body?

Accepted Answer

Catalyzing chemical reactions as enzymes.

Question 14

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

Accepted Answer

Oxygen attracts electrons more strongly than hydrogen, creating an asymmetrical charge distribution.

Question 15

Which of the following is true about the formation of a peptide bond?

Accepted Answer

It is a covalent bond formed between two amino acids.

Question 16

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

Accepted Answer

It stores and provides energy for cellular processes.

Question 17

Which of the following is a correct example of a hydrolysis reaction?

Accepted Answer

Breaking down a disaccharide into two monosaccharides using water.

Question 18

Which of the following statements about nucleic acids is correct?

Accepted Answer

DNA contains the bases adenine, thymine, cytosine, and guanine.

Question 19

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 20

Which of the following best explains why the regulation of pH in body fluids is vital for homeostasis?

Accepted Answer

Enzyme activity and metabolic processes are highly sensitive to changes in pH.

Chemical Level of Organization: Study Notes for Anatomy & Physiology

Study Guide - Practice Questions