2.1 The Rutherford Model of Atomic Structure

Question 1

Name the subatomic particles

Answer 1

Neutrons, Protons, and electrons

Question 2

Discovered electrons, when he studied how gases conduct electricity.

Answer 2

J.J. Thomson

Question 3

f

Question 4

This scientist discovered that the cathode-ray beams could be deflected by magnetic and electric fields

Answer 4

J.J. Thomson

Question 5

Consists of a glass tube from which most of the air has been removed. Electrodes within the tube are attached to the poles of a high-voltage power supply.

Answer 5

Cathode-Ray Tube

Question 6

Streams of electrons emitted by the cathode in a partially evacuated tube.

Answer 6

Cathode Rays

Question 7

A subatomic particle that has a negative charge and negligible mass

Answer 7

Electron

Question 8

This scientist determined the charge of an electron and indirectly, its mass.

Answer 8

Robert Millikan

Question 9

This scientist proposed the Plum Pudding model

Answer 9

J.J. Thomson

Question 10

An atom was a massive, positively charged, but very diffuse sphere with negatively charged electrons distributed throughout

Answer 10

Plum-Pudding Model

Question 11

This scientist discovered a brownish-black mineral that is the principal source of uranium, produces radiation that can be detected using photographic plates

Answer 11

Henri Becquerel

Question 12

The spontaneous emission of high-energy radiation and particles from radioactive materials

Answer 12

Radioactivity

Question 13

a particle that is emitted during radioactive decay and is equivalent in mass and charge to a high-energy electron.

Answer 13

Beta Particles

Question 14

A particle that is emitted during radioactive decay and is equivalent in mass and charge to a 4He nucleus.

Answer 14

Alpha particles

Question 15

This scientist’s contribution included characterizing the properties of alpha and beta particles. His gold-foil experiments led to the modern view of atomic structure.

Answer 15

Ernest Rutherford

Question 16

This scientist was the first to successfully detect and characterize free neutrons

Answer 16

James Chadwick

Question 17

What is the charge of alpha particles?

Answer 17

Positive

Question 18

What is the charge of beta particles?

Answer 18

Negative Charge

Question 19

The cathode-ray tube experiment led to the discovery of which subatomic particle?

Answer 19

Electrons

Question 20

Identify the parts of the cathode-ray tube

Answer 20

A. Magnets

B. Phosphorescent Coating

C. Evacuated Tube

D. High-Voltage Source

Question 21

Label the parts of American physicists Robert Millikan’s oil-drop experiment that advanced J.J. Thomson’s work on subatomic particles.

Answer 21

A. X-Rays

B. Atomizer

C. Oil Drops

D. Microscope

Question 22

The Millikan oil-drop experiment led to the discovery of which of the following?
A. the presence of protons and neutrons

B. the existence of radioactivity and α particles

C. the mass and charge of an electron

D. the presence of a nucleus

Answer 22

C. The mass and charge of an electron

Question 23

Using the figure below, label parts of the Rutherford gold-foil experiment.

Answer 23

A. Thin gold foil

B. Beam of alpha particles

C. Fluorescent Screen

D. Alpha emitter

Question 24

The Rutherford gold-foil experiment led to the discovery of which of the following?
A. The existence of nucleus

B. The mass and charge on an electron

C. The presence of neutrons

D. The presence of electrons

Answer 24

A. The existence of nucleus

Question 25

Which of the following is true in regard to a proton?

Choose one or more:

A.The number of protons determines the identity of an element.

B.A proton has a 1+ charge.

C.A neutral atom must have an equal number of protons and neutrons.

D.A proton has a mass of about 1.0 u.

E.A proton has a 1- charge.

Answer 25

A.The number of protons determines the identity of an element.

B.A proton has a 1+ charge.

D.A proton has a mass of about 1.0 u.

Question 26

Alpha (α) and beta (β) particles emitted by a sample of pitchblende escape through a narrow channel in the shielding surrounding the sample and into an electrical field, as shown in the figure below. γ radiation is also emitted.

Answer 26

Alpha (α) - Red

Beta (β) - Green

γ radiation - Blue

Question 27

The unit used to express the relative masses of atoms and subatomic particles that is exactly 1/12 the mass of 1 atom of carbon with 6 protons and 6 neutrons in its nucleus.

Answer 27

Unified atomic mass units

(also called Daltons)

Question 28

These make up nearly all of an atom’s mass

Answer 28

Neutrons and protons