Question 1

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 2

A neutral atom of magnesium (Mg) has an atomic number of 12 and an atomic mass of 24. How many neutrons does it have?

Accepted Answer

12

Question 3

Which element is most abundant in the human body by weight and is essential for respiration?

Accepted Answer

Oxygen

Question 4

What is the molecular weight of water ($$H_2O) $$given the atomic weights: $$H = 1$$, $$O = 16$$?

Accepted Answer

$$18$$

Question 5

Which type of chemical bond involves the sharing of electron pairs between atoms?

Accepted Answer

Covalent bond

Question 6

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

Accepted Answer

Cation

Question 7

Which element is critical for nerve impulses, muscle contraction, and blood clotting?

Accepted Answer

Calcium

Question 8

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more different elements bonded together in a fixed proportion

Question 9

Which of the following is an example of a decomposition reaction (catabolism)?

Accepted Answer

$$AB \rightarrow A + B$$

Question 10

What is the role of enzymes in chemical reactions within the body?

Accepted Answer

They act as protein catalysts to lower the activation energy

Question 11

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in slightly positive and negative ends

Question 12

A molecule of $$CO_2 is $$formed by sharing two pairs of electrons between carbon and each oxygen atom. What type of covalent bond is this?

Accepted Answer

Double covalent bond

Question 13

Which element is essential for oxygen transport and energy capture in the human body?

Accepted Answer

Iron

Question 14

Which of the following is a trace element in the human body?

Accepted Answer

Zinc

Question 15

Which of the following is NOT an organic compound?

Accepted Answer

Water

Question 16

If a molecule has an unpaired electron in its outermost shell, what is it called?

Accepted Answer

Free radical

Question 17

Which of the following best describes the valence shell of an atom?

Accepted Answer

The outermost shell that determines bonding

Question 18

Which element is a component of hormones produced by the thyroid gland?

Accepted Answer

Iodine

Question 19

Which of the following reactions is an example of a reversible reaction?

Accepted Answer

$$A + B \leftrightarrow AB$$

Question 20

A patient is experiencing muscle cramps due to improper membrane function. Which element deficiency is most likely responsible?

Accepted Answer

Potassium

Chemical Level of Organization: Atoms, Elements, and Chemical Bonds in Anatomy & Physiology

Study Guide - Practice Questions