Question 1

Which statement best describes the difference between an element and a compound?

Accepted Answer

An element is a substance that cannot be broken down by chemical reactions, while a compound consists of two or more elements in a fixed ratio.

Question 2

Which of the following elements makes up the largest percentage of the human body by mass?

Accepted Answer

Oxygen

Question 3

A radioactive isotope of carbon ($$^{14}C) is $$used in radiometric dating. If the half-life of $$^{14}C is 5$$,730 years, how much of a 100 g sample will remain after 11,460 years?

Accepted Answer

25 g

Question 4

Which of the following best explains why sodium chloride (NaCl) forms a crystal lattice in its solid state?

Accepted Answer

Ionic bonds between Na$$^+$$ and Cl$$^-$$ ions create a repeating pattern of positive and negative charges.

Question 5

Which of the following is a trace element required by humans in minute quantities?

Accepted Answer

Iron

Question 6

What determines the chemical behavior of an atom?

Accepted Answer

The distribution of electrons in the atom's electron shells, especially the valence shell

Question 7

Which type of chemical bond involves the sharing of a pair of valence electrons between two atoms?

Accepted Answer

Covalent bond

Question 8

A molecule of water ($$H_2O) $$has polar covalent bonds. What does this mean?

Accepted Answer

Oxygen is more electronegative and pulls the shared electrons closer, creating partial charges.

Question 9

Which of the following best describes a hydrogen bond?

Accepted Answer

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

Question 10

Which scenario best illustrates the concept of emergent properties in compounds?

Accepted Answer

Sodium is a metal and chlorine is a poisonous gas, but together they form edible table salt (NaCl).

Question 11

If an atom has an atomic number of 8 and a mass number of 16, how many neutrons does it have?

Accepted Answer

8

Question 12

Which of the following statements about chemical reactions is correct?

Accepted Answer

Chemical reactions involve the making and breaking of chemical bonds.

Question 13

Photosynthesis is represented by the following equation: $$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2. $$What are the reactants in this reaction?

Accepted Answer

$$CO_2$$ and $$H_2O$$

Question 14

Which of the following best describes chemical equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate.

Question 15

Which of the following weak chemical interactions is responsible for the ability of a gecko to climb smooth surfaces?

Accepted Answer

Van der Waals interactions

Question 16

Why are elements with a full valence shell chemically inert?

Accepted Answer

They do not need to gain, lose, or share electrons to achieve stability.

Question 17

Which property of atoms allows morphine to mimic endorphins and bind to the same receptors in the brain?

Accepted Answer

Similar molecular shape due to the arrangement of atoms' orbitals

Question 18

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 19

Which of the following is true about electron orbitals?

Accepted Answer

An orbital is the three-dimensional space where an electron is found 90% of the time.

Question 20

A patient is given a radioactive tracer for a PET scan. Which property of radioactive isotopes makes this possible?

Accepted Answer

They decay spontaneously, emitting particles and energy that can be detected.

Chapter 2: The Chemical Context of Life – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards