Question 1

Which of the following best explains why water molecules are able to form hydrogen bonds with each other?

Accepted Answer

Water molecules are polar, with partial positive and negative charges on different atoms.

Question 2

A radioactive isotope of carbon, $$^{14}C$$, is used in medical imaging. Which property makes it different from the most common carbon isotope, $$^{12}C$$?

Accepted Answer

$$^{14}C$$ has more neutrons than $$^{12}C.$$

Question 3

Which of the following best describes the difference between a covalent bond and an ionic bond?

Accepted Answer

A covalent bond involves the sharing of electrons, while an ionic bond involves the transfer of electrons.

Question 4

Which of the following elements is NOT one of the four major elements found in living organisms?

Accepted Answer

Calcium

Question 5

A molecule of methane ($$CH_4) $$has which of the following types of bonds between its atoms?

Accepted Answer

Nonpolar covalent bonds

Question 6

Which of the following best describes the role of trace elements in the human body?

Accepted Answer

They are required in small amounts but are essential for proper physiological function.

Question 7

If an atom has an atomic number of 8 and a mass number of 18, how many neutrons does it have?

Accepted Answer

10

Question 8

Which of the following statements about electronegativity is correct?

Accepted Answer

Electronegativity is the ability of an atom to attract electrons in a chemical bond.

Question 9

Which of the following best explains why sodium chloride ($$NaCl) $$dissolves easily in water?

Accepted Answer

Water is polar and stabilizes the separated sodium and chloride ions through ion-dipole interactions.

Question 10

A patient is exposed to a radioactive isotope during a diagnostic test. Which property of radioactive isotopes allows them to be used in medical imaging?

Accepted Answer

They emit energy that can be detected by imaging equipment.

Question 11

Which of the following best describes a van der Waals interaction?

Accepted Answer

A weak attraction between molecules due to temporary partial charges.

Question 12

Which of the following scenarios best illustrates the concept of chemical equilibrium?

Accepted Answer

A reaction in which the rate of the forward reaction equals the rate of the reverse reaction.

Question 13

Which of the following is a correct statement about isotopes?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 14

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond in which electrons are shared unequally, resulting in partial charges on the atoms.

Question 15

A molecule has the formula $$C_2H_6O. $$Which of the following statements is true about its structure?

Accepted Answer

It can have different structural formulas (isomers) with the same molecular formula.

Question 16

Which of the following best explains why oxygen is more electronegative than hydrogen?

Accepted Answer

Oxygen has more protons, which increases its ability to attract electrons.

Question 17

Which of the following is the best example of a compound?

Accepted Answer

H$$_2O$$

Question 18

A molecule of ammonia ($$NH_3) $$has a trigonal pyramidal shape. Which concept explains this molecular geometry?

Accepted Answer

The presence of lone pairs of electrons on the nitrogen atom causes repulsion, resulting in a trigonal pyramidal shape.

Question 19

Which of the following best describes the relationship between atomic number and atomic mass?

Accepted Answer

Atomic number is the number of protons, while atomic mass is the sum of protons and neutrons.

Question 20

Which of the following best explains why noble gases are chemically inert?

Accepted Answer

They have a full valence electron shell, making them stable and unlikely to react.

The Chemical Context of Life: Study Notes for General Biology

Study Guide - Practice Questions

Study Guide - Flashcards