Question 1

Which of the following best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons.

Question 2

Which of the following is a medical use of isotopes?

Accepted Answer

Using $$^{99m}Tc$$ for imaging organs in nuclear medicine.

Question 3

Which of the following is NOT a major element found in the human body?

Accepted Answer

Gold (Au)

Question 4

Which type of chemical bond is the strongest?

Accepted Answer

Nonpolar covalent bond

Question 5

Which molecule is an example of a polar covalent bond?

Accepted Answer

H$$_2O$$

Question 6

Which of the following best describes an enzyme's function in a chemical reaction?

Accepted Answer

Enzymes lower the activation energy and speed up the reaction.

Question 7

Which of the following is a component of an enzyme and its function?

Accepted Answer

Active site: binds to the substrate and catalyzes the reaction.

Question 8

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

Accepted Answer

Serves as a solvent for biochemical reactions.

Question 9

A solution has a pH of 2. Which of the following statements is correct?

Accepted Answer

The solution is acidic and has a high concentration of H$$^+$$ ions.

Question 10

Which body fluid has a pH closest to neutral (pH 7)?

Accepted Answer

Blood

Question 11

Which of the following best describes how a buffer system works in blood?

Accepted Answer

Buffers maintain blood pH by neutralizing excess acids or bases.

Question 12

What is the primary buffer system that controls blood pH?

Accepted Answer

Bicarbonate buffer system

Question 13

Which of the following is an example of an ionic bond?

Accepted Answer

NaCl

Question 14

Which statement correctly differentiates between acids and bases?

Accepted Answer

Acids release H$$^+$$ ions, bases release OH$$^-$$ ions.

Question 15

Which of the following best describes a molecule?

Accepted Answer

A substance composed of two or more atoms chemically bonded together.

Question 16

Which of the following is a real-life example of a nonpolar covalent bond?

Accepted Answer

O$$_2$$

Question 17

A patient receives a radioactive isotope for thyroid imaging. Which property of isotopes makes this possible?

Accepted Answer

Isotopes have identical chemical properties but different nuclear stability.

Question 18

Which of the following is a multi-step problem: If a solution has a pH of 5, what is the concentration of H$$^+$$ ions? (Use $$[H^+] = 10$$^{-pH}$$)

Accepted Answer

$$[H^+] = 10$$^{-5}$$ = 0.00001 M $$

Question 19

Which of the following best describes a valence number?

Accepted Answer

The number of electrons in the outermost shell.

Question 20

Which of the following is a correct example of a chemical reaction type?

Accepted Answer

Decomposition: $$2H_2O \rightarrow 2H_2 + O_2$

Chapter 2 Study Guide: Chemistry and Measurements (Sections 2.1–2.4)

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