$$\text{Atomic mass} = \text{Number of protons} + \text{Number of neutrons}$$

Question 1

Which subatomic particle determines the atomic number of an element, and why is this significant in identifying elements?

Accepted Answer

Protons; because the number of protons defines the atomic number and thus the element itself.

Question 2

A neutral atom of sodium (Na) has an atomic number of 11 and an atomic mass of 23. How many neutrons does it have?

Accepted Answer

12

Question 3

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed between oppositely charged ions due to electron transfer.

Question 4

If an atom has 17 protons and 18 electrons, what is its charge and what is it called?

Accepted Answer

It has a -1 charge and is called an anion.

Question 5

Which property of water is MOST important for maintaining body temperature during exercise?

Accepted Answer

Its high heat capacity.

Question 6

A solution has a pH of 2.5. Which of the following statements is TRUE?

Accepted Answer

It is acidic and similar to the environment of the human stomach.

Question 7

Which equation correctly represents the calculation of atomic mass?

Accepted Answer

$$	ext{Atomic mass} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Question 8

Which type of chemical bond is responsible for the unique properties of water, such as surface tension and high boiling point?

Accepted Answer

Hydrogen bonds

Question 9

A buffer system in the human body helps maintain homeostasis by:

Accepted Answer

Minimizing changes in pH.

Question 10

Which of the following is a correct statement about electrolytes?

Accepted Answer

Electrolytes are substances that can conduct electrical current and are necessary for nerve and muscle function.

Question 11

Which of the following is NOT a function of proteins in the human body?

Accepted Answer

Storing genetic information

Question 12

Which biological macromolecule is primarily responsible for storing genetic information?

Accepted Answer

Nucleic acids

Question 13

A patient is diagnosed with lactose intolerance. Which enzyme is deficient, and what is its normal function?

Accepted Answer

Lactase; breaks down lactose into galactose and glucose.

Question 14

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond where electrons are unequally shared, causing partial charges on atoms.

Question 15

Which of the following molecules is hydrophobic and does NOT dissolve in water?

Accepted Answer

Lipids

Question 16

Which of the following is a correct example of catabolism?

Accepted Answer

Digestion of lactose into galactose and glucose

Question 17

Which of the following ions is most important for the conduction of electrical signals in nerves?

Accepted Answer

Sodium ions ($$\mathrm{Na^+})$$

Question 18

Which of the following is the correct formula for calculating pH?

Accepted Answer

$$\mathrm{pH} = -\log_{10}[\mathrm{H^+}]$$

Question 19

Which biological macromolecule is the main energy source for most cells?

Accepted Answer

Carbohydrates

Question 20

A patient has a blood pH of 7.1. Which of the following statements is correct?

Accepted Answer

The blood is more acidic than normal and may indicate acidosis.

Chapter 2 – The Chemistry of Life: Foundations for Anatomy & Physiology

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