Question 1

Which statement best summarizes Dalton’s atomic theory as it relates to the composition of compounds?

Accepted Answer

Atoms of different elements combine in simple, whole-number ratios to form compounds.

Question 2

J.J. Thomson’s experiments with cathode rays led to the discovery of which subatomic particle, and what property did he determine about it?

Accepted Answer

Electron; it is negatively charged and much lighter than a proton.

Question 3

Rutherford’s gold foil experiment disproved the plum-pudding model because:

Accepted Answer

Some alpha particles were deflected at large angles, indicating a dense, positively charged nucleus.

Question 4

Which of the following best describes the distribution of mass and volume in the nuclear model of the atom?

Accepted Answer

Most of the mass is in the nucleus, while most of the volume is empty space occupied by electrons.

Question 5

If a proton had the mass of a baseball, how would the mass of an electron compare?

Accepted Answer

The electron would have the mass of a rice grain.

Question 6

Which equation correctly represents the charge neutrality of an atom?

Accepted Answer

$$1+ + 1- = 0$$

Question 7

An atom of aluminum has 13 protons. What is its atomic number, and what does this number represent?

Accepted Answer

13; the number of protons in the nucleus

Question 8

Which of the following is a correct statement about elements and their symbols?

Accepted Answer

The symbol for sodium is Na, derived from its Latin name natrium.

Question 9

Which real-world application demonstrates the ability to manipulate individual atoms, as discussed in the study materials?

Accepted Answer

IBM’s creation of the world’s smallest movie, 'A Boy and His Atom', using a scanning tunneling microscope.

Question 10

Which of the following best explains why a grain of sand made entirely of atomic nuclei would have an enormous mass?

Accepted Answer

Atomic nuclei are extremely dense, containing most of the atom’s mass in a tiny volume.

Question 11

Which of the following is NOT a part of Dalton’s atomic theory?

Accepted Answer

Atoms can be created or destroyed in chemical reactions.

Question 12

A scientist discovers a new element and names it after their home country. Which of the following elements was named in a similar way?

Accepted Answer

Polonium

Question 13

Which of the following statements about electrical charge is correct?

Accepted Answer

Positive and negative charges attract each other, while like charges repel.

Question 14

Which scientist is credited with the discovery of the nucleus through the gold foil experiment?

Accepted Answer

Ernest Rutherford

Question 15

Which of the following best describes the relationship between protons, neutrons, and electrons in a neutral atom?

Accepted Answer

The number of protons equals the number of electrons.

Question 16

Which of the following is a correct comparison of the relative masses of subatomic particles?

Accepted Answer

Protons and neutrons have similar masses, while electrons are much lighter.

Question 17

Which of the following elements is named after a scientist?

Accepted Answer

Curium

Question 18

A sample contains atoms with 17 protons, 18 neutrons, and 17 electrons. Which element is this, and what is its atomic number?

Accepted Answer

Chlorine; atomic number 17

Question 19

Which of the following best explains why the periodic table is organized by atomic number rather than atomic mass?

Accepted Answer

The atomic number uniquely identifies the number of protons in each element.

Question 20

Which of the following is a real-life implication of the density of atomic nuclei, as discussed in the study materials?

Accepted Answer

Black holes and neutron stars are believed to be composed of extremely dense nuclear matter.

Atoms and Elements: Foundations of Modern Chemistry

Study Guide - Practice Questions