Question 1

Which of the following statements best explains why the properties of formic acid differ from those of its constituent elements?

Accepted Answer

Formic acid's properties result from the way its atoms are bonded together and the arrangement of electrons.

Question 2

Which of the following is the best definition of an element in the context of biology?

Accepted Answer

A substance that cannot be broken down into other substances by chemical reactions.

Question 3

Which four elements make up approximately 96% of living matter?

Accepted Answer

Carbon, hydrogen, oxygen, and nitrogen

Question 4

A scientist is studying a plant community that thrives in soil with high concentrations of toxic elements. What biological principle does this scenario best illustrate?

Accepted Answer

The evolution of tolerance to toxic elements

Question 5

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 6

An atom of carbon has 6 protons and 8 neutrons. What is its mass number?

Accepted Answer

$$14$$

Question 7

Radioactive isotopes are useful in medicine because:

Accepted Answer

They can be used as tracers to track atoms through metabolic processes.

Question 8

Which equation correctly represents the formation of sodium chloride from its elements?

Accepted Answer

$$\mathrm{Na} + \mathrm{Cl} \rightarrow \mathrm{NaCl}$$

Question 9

Which of the following best describes a covalent bond?

Accepted Answer

The sharing of a pair of valence electrons between two atoms

Question 10

What is the main difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

Polar covalent bonds have unequal sharing of electrons, while nonpolar covalent bonds have equal sharing.

Question 11

Which of the following is true about ionic bonds?

Accepted Answer

Ionic bonds result from the attraction between oppositely charged ions.

Question 12

A radioactive isotope has a half-life of 10 years. If you start with 100 grams, how much will remain after 30 years?

Accepted Answer

$$12.5$$ grams

Question 13

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 14

Which statement about chemical reactions is correct?

Accepted Answer

Chemical reactions involve both the making and breaking of chemical bonds.

Question 15

Photosynthesis is represented by which of the following chemical equations?

Accepted Answer

$$6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2$$

Question 16

Which of the following best explains why trace elements are important for life?

Accepted Answer

Trace elements are required in minute quantities but are essential for specific biological functions.

Question 17

Which of the following is true about chemical equilibrium in a reaction?

Accepted Answer

At equilibrium, the forward and reverse reactions occur at the same rate.

Question 18

Which of the following best describes the role of molecular shape in biological function?

Accepted Answer

Molecular shape determines how biological molecules recognize and respond to one another.

Question 19

Which of the following is a real-world application of van der Waals interactions?

Accepted Answer

The ability of gecko toe hairs to adhere to surfaces

Question 20

A molecule of water ($$\mathrm{H}_2\mathrm{O}) is $$best described as:

Accepted Answer

A polar molecule with unequal sharing of electrons between hydrogen and oxygen

The Chemical Context of Life (Campbell Biology, Chapter 2) - Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards