Section 7 - Atomic Physics

Question 1

What three things are in an atom?

Answer 1

Nucleus
Proton
Electron

Question 2

What part of a atom is negatively charged?

Answer 2

The electron

Question 3

What is the part of an atom with a positive charge?

Answer 3

Proton

Question 4

What is found in the nucleus of an atom?

Answer 4

Protons and neutrons

Question 5

Describe the structure of an atom?

Answer 5

An atom is a positively charged nucleus that contains protons and electrons with negatively charge electrons orbiting the nucleus

Question 6

Explain the alpha scattering experiment?

Answer 6

A beam of alpha particles were shot at a thing sheet of gold.
Alpha particles are positively charged so returned atoms must be repelled.

Question 7

What were the results of the alpha particles experiment?

Answer 7

Most alpha particles went straight through, some were deflected, and a tiny proportion bounced back

Question 8

What do the reuse kits from the alpha particle experiment show?

Answer 8

• the nucleus is very small and surrounded by empty space
• a nucleus is positively charged as some particles were deflected
• a nucleus is very dense and contains most of the atoms mass

Question 9

How do you find the proton number?

Answer 9

The proton number is the atomic number

Question 10

What is the nucleon number?

Answer 10

The number of protons and neutrons - the atomic mass

Question 11

What is the letter notation for the element symbol?

Answer 11

X

Question 12

What is the letter notation for the atomic mass?

Answer 12

A

Question 13

What is the letter notation for atomic number?

Answer 13

Z

Question 14

What is an isotope?

Answer 14

An isotope is an atom with the same number of protons but a different number of electrons

Question 15

What is radioactive decay?

Answer 15

Radioactive decay is the process in which unstable nuclei change to become more stable by emitting ionising radiation. This process is spontaneous and random

Question 16

What is background radiation?

Answer 16

Background radiation is the radiation that is present all around in the environment

Question 17

Name four background radiation examples?

Answer 17

• natural gas - radon
• rocks and buildings
• food and drink
• cosmic rays

Question 18

How can nuclear radiation be detected?

Answer 18

Using a GM tube - detector and counter

Question 19

What is radiation measured in?

Answer 19

Counts. Or counts per minute

Question 20

Describe how radiation is emitted?

Answer 20

Radiation is emitted at a randomly and in any direction

Question 21

What are the three types of radiation?

Answer 21

Gamma
Beta
Alpha

Question 22

What is the ionising power of the three emissions?

Answer 22

Alpha - strong
Beta - moderate
Gamma - weak

Question 23

What is the penetration power of all the emissions?

Answer 23

Alpha - weak - few cm in air or sheet of paper
Beta - moderate - few metres or thin aluminium
Gamma - strong - long distance or thick lead

Question 24

Describe an alpha particle

Answer 24

An alpha particle consists of two protons and two neutrons (the same as a helium nucleus) it has no electrons

Question 25

Describe a beta particle

Answer 25

A beta particle is a fast moving electron

Question 26

Describe gamma radiation

Answer 26

Gamma are waves of the electromagnetic spectrum

Question 27

What types of decay produce a new element

Answer 27

Alpha and beta

Question 28

Describe alpha decay

Answer 28

Alpha decay is when a nucleus emits an alpha particle. The nucleus’ proton number will decrease by 2 and atomic mass decrease by 4

Question 29

Describe beta decay

Answer 29

Beta decay is when a neutron turns into a proton and an electron.
The electron is the beta particle and the proton moves back into the nucleus. The proton increase by 1 and the atomic number stays same

Question 30

What are three thing that make a nucleus unstable?

Answer 30

If they have too much energy
If they have too many neutrons
If they are too heavy

Question 31

How is a alpha particle written

Answer 31

letter a with atomic number 4 and proton number 2

Question 32

How is a beta particle written

Answer 32

B with a tail. Atomic mass 0 and proton number -1

Question 33

What is half life?

Answer 33

Half life is the time taken for half the nuclei of that isotope of a sample to decay