Question 1

Which of the following statements best describes the atomic hypothesis as confirmed by Einstein's explanation of Brownian motion?

Accepted Answer

Atoms are in perpetual motion and their existence explains the jittery movement of particles suspended in a fluid.

Question 2

Which of the following is NOT a characteristic of atoms?

Accepted Answer

Atoms are visible to the naked eye.

Question 3

Which of the following best explains why the diameter of atoms generally decreases from left to right across a period in the periodic table?

Accepted Answer

The increasing nuclear charge pulls electrons closer, shrinking the atomic radius.

Question 4

Which of the following is true about isotopes?

Accepted Answer

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

Question 5

A certain atom has 17 protons, 18 neutrons, and 17 electrons. What is its mass number?

Accepted Answer

$$35$$

Question 6

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

Accepted Answer

A compound has properties different from its constituent elements, while a mixture retains the properties of its components.

Question 7

Which of the following is a correct statement about ions?

Accepted Answer

A positive ion has fewer electrons than protons.

Question 8

Which of the following elements is NOT one of the five most common elements in living things?

Accepted Answer

Iron

Question 9

Which of the following statements about antimatter is correct?

Accepted Answer

When matter and antimatter meet, they annihilate each other.

Question 10

Which of the following best describes the arrangement of the periodic table?

Accepted Answer

Elements are arranged by increasing atomic number, with each row representing a new electron shell.

Question 11

A molecule of ammonia ($$NH_3) $$consists of:

Accepted Answer

One atom of nitrogen and three atoms of hydrogen.

Question 12

Which of the following is a real-world example of a chemical reaction?

Accepted Answer

Iron rusting when exposed to oxygen.

Question 13

Which of the following statements about dark matter is correct?

Accepted Answer

Dark matter interacts gravitationally and makes up about 23% of the universe's mass.

Question 14

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

Accepted Answer

Protons and neutrons are made of quarks.

Question 15

If an atom has 12 protons, 12 neutrons, and 10 electrons, what is its net charge?

Accepted Answer

$$+2$$

Question 16

Which of the following is true about noble gases?

Accepted Answer

Their outer electron shells are filled to capacity.

Question 17

Which of the following best describes a molecule?

Accepted Answer

A molecule is two or more atoms bonded together.

Question 18

Which of the following is a property of electrons in an atom?

Accepted Answer

They are bound to the nucleus by electrical forces.

Question 19

Which of the following is a correct statement about the composition of air?

Accepted Answer

Air is a mixture of several gases, mostly nitrogen and oxygen.

Question 20

Which of the following best describes the process of photosynthesis in terms of atomic rearrangement?

Accepted Answer

Atoms are rearranged to form new molecules, using energy from sunlight.

Chapter 11: The Atomic Nature of Matter – Study Notes

Study Guide - Practice Questions