Question 1

Which of the following statements best describes an atom?

Accepted Answer

An atom is the smallest unit of matter that retains the properties of an element.

Question 2

A sodium atom (Na) has 11 protons and 11 electrons. If it loses one electron, what is the resulting charge and what is this particle called?

Accepted Answer

It becomes a cation with a charge of $$+1.$$

Question 3

Which subatomic particle is responsible for the chemical behavior of an atom and where is it located?

Accepted Answer

Electron; located in shells orbiting the nucleus

Question 4

Radioactive isotopes are used in medical imaging because:

Accepted Answer

They emit radiation that can be detected to visualize internal body structures.

Question 5

Which of the following best explains why water ($$\mathrm{H_2O}) is a $$polar molecule?

Accepted Answer

Oxygen has a stronger pull on shared electrons, creating regions of partial positive and negative charge.

Question 6

What type of bond is formed when one atom donates an electron to another atom, resulting in oppositely charged ions that attract each other?

Accepted Answer

Ionic bond

Question 7

A molecule of methane ($$\mathrm{CH_4$}) is $$formed by carbon sharing electrons with four hydrogen atoms. What type of bond is present in methane?

Accepted Answer

Nonpolar covalent bonds

Question 8

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a slightly positive hydrogen atom and a slightly negative atom in another molecule

Question 9

If an atom has 8 protons, 8 neutrons, and 10 electrons, what is its net charge?

Accepted Answer

$$-2$$

Question 10

Which of the following is true about ATP (adenosine triphosphate) in human cells?

Accepted Answer

ATP stores energy in its phosphate bonds, which is released when a phosphate group is removed.

Question 11

Which of the following best explains why noble gases (such as helium and neon) are chemically inert?

Accepted Answer

Their valence shells are full, so they do not tend to gain, lose, or share electrons.

Question 12

A patient is injected with a radioactive isotope for a PET scan. What property of the isotope allows it to be used for imaging?

Accepted Answer

It emits radiation that can be detected by imaging equipment.

Question 13

Which of the following is a compound?

Accepted Answer

Carbon dioxide ($$\mathrm{CO_2$})$$

Question 14

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

Accepted Answer

A molecule consists of two or more atoms bonded together, while a compound consists of two or more different elements bonded together.

Question 15

Which of the following best explains why ionic bonds are generally weaker in water than in a dry environment?

Accepted Answer

Water molecules surround and separate the ions, reducing the electrostatic attraction between them.

Question 16

A molecule of oxygen gas ($$\mathrm{O_2$}) is $$held together by which type of bond?

Accepted Answer

Nonpolar covalent bond

Question 17

Which of the following scenarios best illustrates the formation of a polar covalent bond?

Accepted Answer

A water molecule, where oxygen shares electrons unequally with hydrogen

Question 18

If a radioactive isotope of iodine is used to treat thyroid cancer, which property of the isotope is most important for its therapeutic effect?

Accepted Answer

It emits radiation that can destroy cancerous cells.

Question 19

Which of the following best describes the process of ATP hydrolysis in cells?

Accepted Answer

ATP is broken down into ADP and inorganic phosphate ($$\mathrm{P_i}$$), releasing energy.

Question 20

A patient has a mutation that causes their cells to be unable to form hydrogen bonds. Which of the following would most likely be affected?

Accepted Answer

The structure and properties of water in their body

Basic Chemistry for Anatomy & Physiology: Atoms, Subatomic Particles, and Chemical Bonds

Study Guide - Practice Questions