Question 1

Which of the following best describes why sodium chloride (NaCl) has properties different from both sodium and chlorine?

Accepted Answer

Because a compound’s properties depend on how its atoms are bonded together.

Question 2

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

Accepted Answer

Carbon, hydrogen, oxygen, nitrogen

Question 3

A patient is diagnosed with goiter, a swelling of the thyroid gland. Which trace element deficiency is most likely responsible?

Accepted Answer

Iodine

Question 4

Which statement about isotopes is correct?

Accepted Answer

Isotopes of an element have different numbers of neutrons.

Question 5

What is the atomic mass of an atom with 11 protons, 12 neutrons, and 11 electrons?

Accepted Answer

$$23$$

Question 6

Which of the following best explains why radioactive isotopes are useful in medical imaging?

Accepted Answer

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

Question 7

Which of the following is true about electron orbitals?

Accepted Answer

Each orbital can hold a maximum of 2 electrons.

Question 8

What determines the chemical behavior of an atom?

Accepted Answer

The distribution of electrons in electron shells

Question 9

Which of the following best describes a covalent bond?

Accepted Answer

A sharing of a pair of valence electrons between two atoms

Question 10

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

Accepted Answer

Polar covalent bond

Question 11

Which of the following is an example of a real-world application of radioactive isotopes?

Accepted Answer

Determining the age of fossils using radiometric dating

Question 12

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

Accepted Answer

A compound can be broken down by chemical reactions, but an element cannot.

Question 13

Which of the following statements about energy levels of electrons is correct?

Accepted Answer

Electrons farther from the nucleus have higher potential energy.

Question 14

Which of the following is a trace element required by humans and is necessary for thyroid function?

Accepted Answer

Iodine

Question 15

Which of the following best describes a hydrogen bond?

Accepted Answer

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

Question 16

Which of the following is true about chemical reactions?

Accepted Answer

They involve the making and breaking of chemical bonds.

Question 17

What is the maximum number of electrons that can be held in the second energy shell of an atom?

Accepted Answer

$$8$$

Question 18

Which of the following best explains why water molecules are polar?

Accepted Answer

Oxygen is more electronegative than hydrogen, causing unequal sharing of electrons.

Question 19

Which of the following is an example of a weak chemical interaction important in biological molecules?

Accepted Answer

Hydrogen bond

Question 20

A radioactive isotope has a half-life of 1 billion years. If a rock sample originally contained 100 grams of this isotope, how much would remain after 2 billion years?

Accepted Answer

$$25$$ grams

Chapter 2: The Chemical Context of Life – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards