Section 2.3- Subatomic Particles

Question 1

smaller particles of matter that make up the atom

Answer 1

subatomic particles

Question 2

two chemists in the early 1800s that used electricity to decompose chemical compounds

Answer 2

Faraday
Humphrey

Question 3

physicist who proposed that units of electrical charge– negatively charged particles– were associated with atoms

Answer 3

Stoney

Question 4

Stoney named his proposed charged particles

Answer 4

electrons

Question 5

the negatively charged electrical lead, or electrode in which invisible rays emanate from

Answer 5

cathode

Question 6

positive electrode in which invisible rays travel toward

Answer 6

anode

Question 7

the phenomenon of cathode rays was first discovered by

Answer 7

Julius Plucker

Question 8

mysterious rays that emanate from the cathode

Answer 8

cathode rays

Question 9

a gas-discharge tube is also known as a

Answer 9

cathode-ray tube (CRT)

Question 10

English physicist and chemist who designed an improved tube in which the cathode rays missed the anode and struck the end of the tube instead, causing it to glow

Answer 10

Sir William Crookes

Question 11

American physicist who was able to determine an electron’s charge, which in turn allowed the electron’s mass to be calculated

Answer 11

Robert Millikan

Question 12

negatively charged particle that was discovered through the study of cathode rays

Answer 12

electron

Question 13

positively charged particle that was discovered through the study of canal rays

Answer 13

proton

Question 14

he pictured the atom as a sphere of positive charge in which the negative electron were embedded like raisins in a pudding (plum-pudding model)

Answer 14

J J Thompson

Question 15

the dense central core of the atom

Answer 15

nucleus

Question 16

model which states that only when an ion bullet came near a nucleus would it be repelled and deflected; most of the ions would pass through undeflected because they would encounter mostly empty space or very light electrons

Answer 16

nuclear or planetary model

Question 17

conclusively demonstrated the existence of the neutron

Answer 17

Sir James Chadwick

Question 18

two types of subatomic particles that are found in the dense central core of an atom are

Answer 18

proton
neutron

Question 19

building blocks of the atom’s nucleus

Answer 19

protons and neutrons

Question 20

according to current theory, protons and neutrons are composed of what type of smaller particles

Answer 20

quarks

Question 21

the two types of quark that are thought to compose protons and neutrons

Answer 21

up quark
down quark