Question 1

Which of the following statements best explains why atoms are electrically neutral?

Accepted Answer

Atoms have an equal number of protons and electrons.

Question 2

Which subatomic particle determines the identity of an element?

Accepted Answer

Proton

Question 3

A radioactive isotope of carbon, carbon-14, is used in radiocarbon dating. What makes carbon-14 different from carbon-12?

Accepted Answer

Carbon-14 has more neutrons than carbon-12.

Question 4

Which of the following best describes a compound?

Accepted Answer

A substance consisting of two or more different elements in a fixed ratio.

Question 5

Which element is the most abundant in the human body by mass?

Accepted Answer

Oxygen

Question 6

A patient is given a radioactive tracer for a PET scan. What property of the tracer allows it to be detected in the body?

Accepted Answer

It emits radioactive particles and energy.

Question 7

Which of the following is a trace element required to prevent goiter in humans?

Accepted Answer

Iodine

Question 8

If an atom has an atomic number of 11 and a mass number of 23, how many neutrons does it have?

Accepted Answer

$$23 - 11 = 12$$

Question 9

Why are radioactive isotopes useful in medical imaging?

Accepted Answer

They can be tracked in the body due to their emission of detectable particles.

Question 10

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

Accepted Answer

Emergent properties arise when elements combine to form compounds.

Question 11

Which of the following is NOT a characteristic of an element?

Accepted Answer

It can be broken down into simpler substances by chemical means.

Question 12

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have different numbers of neutrons.

Question 13

A home is found to have high levels of radon gas. What is the source of this gas and what is a potential health risk?

Accepted Answer

Radon is a radioactive gas from uranium decay in soil and can cause lung cancer.

Question 14

Which of the following best describes the relationship between protons, neutrons, and atomic mass?

Accepted Answer

Atomic mass is the sum of protons and neutrons.

Question 15

Which of the following is a real-world application of radioactive isotopes in biology?

Accepted Answer

Using carbon-14 to date ancient fossils.

Question 16

Which of the following elements is considered a trace element in the human body?

Accepted Answer

Iron

Question 17

A lithium atom has 3 protons, 4 neutrons, and 3 electrons. What is its atomic number and mass number?

Accepted Answer

Atomic number = 3, Mass number = 7

Question 18

Which of the following best explains why the nucleus of an atom is so small compared to the overall size of the atom?

Accepted Answer

Most of the atom's volume is empty space occupied by the electron cloud.

Question 19

Which of the following is a correct statement about the periodic table?

Accepted Answer

Elements are arranged by increasing atomic number.

Question 20

Which of the following is an example of an emergent property?

Accepted Answer

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

Chapter 2: The Chemical Basis of Life – Elements, Atoms, and Compounds

Study Guide - Practice Questions