Question 1

Which of the following best describes an element?

Accepted Answer

A substance that contains only one type of atom.

Question 2

What is the atomic number of an element equal to?

Accepted Answer

The number of protons only.

Question 3

An oxygen atom has an atomic number of 8 and a mass number of 16. How many neutrons does it have?

Accepted Answer

$$16 - 8 = 8$$

Question 4

Which of the following statements about electron energy shells is correct?

Accepted Answer

Shells closer to the nucleus are lower in energy than distant shells.

Question 5

According to the octet rule, why is neon (Ne) unreactive?

Accepted Answer

It has 8 valence electrons and its valence shell is full.

Question 6

What is an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 7

Which of the following is a property of water that is essential for life and results from hydrogen bonding?

Accepted Answer

High surface tension.

Question 8

Which of the following best describes a covalent bond?

Accepted Answer

An interaction between two atoms resulting from the sharing of electrons.

Question 9

What type of bond holds the hydrogens and oxygen of a water molecule together?

Accepted Answer

Covalent bonds.

Question 10

Which of the following is true about ionic bonds?

Accepted Answer

They are electrical attractions between oppositely charged ions.

Question 11

Which of the following is a function of carbohydrates in living organisms?

Accepted Answer

Energy storage and structural support.

Question 12

Which of the following reactions breaks down polymers into monomers?

Accepted Answer

Hydrolysis.

Question 13

Which of the following best describes a buffer?

Accepted Answer

A substance that resists changes in pH when acids or bases are added.

Question 14

Which of the following is a property of lipids?

Accepted Answer

They are hydrophobic and insoluble in water.

Question 15

Which of the following is true about phospholipids?

Accepted Answer

They have a hydrophilic head and hydrophobic tails.

Question 16

Which of the following best describes the primary structure of a protein?

Accepted Answer

The specific sequence of amino acids.

Question 17

Which of the following is a component of a nucleotide?

Accepted Answer

A nitrogenous base, a phosphate group, and a sugar.

Question 18

Which of the following statements about DNA structure is correct?

Accepted Answer

The nucleic acid strands in a DNA molecule are oriented antiparallel to each other.

Question 19

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water.

Question 20

Which of the following is a property of water that allows it to moderate temperature?

Accepted Answer

High specific heat.

Chemical Principles in Microbiology: Structured Study Notes

Study Guide - Practice Questions