Question 1

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 2

Which type of chemical bond is primarily responsible for the three-dimensional structure of DNA and proteins?

Accepted Answer

Hydrogen bonds

Question 3

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

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 4

Which of the following statements about ionic bonds is correct?

Accepted Answer

Ionic bonds form between atoms with vastly different electronegativities.

Question 5

Which element is the principal cation inside cells and is essential for nerve impulses?

Accepted Answer

Potassium (K)

Question 6

What is the main reason electrons do not fly away from the nucleus despite moving at high speeds?

Accepted Answer

The electrical attraction between negatively charged electrons and positively charged protons

Question 7

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally due to differences in electronegativity

Question 8

Which of the following elements is a component of nucleic acids and ATP?

Accepted Answer

Phosphorus (P)

Question 9

A molecule of water (H$$_2O) is $$held together by which type of bond between hydrogen and oxygen?

Accepted Answer

Polar covalent bond

Question 10

Which of the following is true about the relative strengths of chemical bonds in biological systems?

Accepted Answer

Nonpolar covalent bonds are generally the strongest

Question 11

Which of the following best explains why salts such as NaCl dissociate in water?

Accepted Answer

Water forms hydrogen bonds with the ions, separating them

Question 12

Which of the following is a correct definition of a compound?

Accepted Answer

A molecule composed of more than one element

Question 13

Which of the following elements is essential for plant growth but not a major component of organic molecules?

Accepted Answer

Boron (B)

Question 14

Which of the following best describes the role of valence electrons in chemical bonding?

Accepted Answer

They are responsible for the chemical behavior of atoms

Question 15

Which of the following is a real-life application of radioactive isotopes in microbiology?

Accepted Answer

They are used as tracers to study metabolic pathways

Question 16

Which of the following best explains why carbon is the backbone of organic molecules?

Accepted Answer

Carbon can form four nonpolar covalent bonds with other atoms

Question 17

A patient is exposed to a radioactive isotope that decays by releasing energy. Which property of the isotope is responsible for this behavior?

Accepted Answer

It has an unstable nucleus

Question 18

Which of the following elements is a principal anion outside cells and is important for maintaining osmotic balance?

Accepted Answer

Chlorine (Cl)

Question 19

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

Accepted Answer

A compound is a molecule composed of more than one element

Question 20

Which of the following is a multi-step process involving both ionic and hydrogen bonds in a biological context?

Accepted Answer

The dissociation of NaCl in water and subsequent hydration of ions

The Chemistry of Microbiology: Structured Study Notes Ch2 - 1

Study Guide - Practice Questions