Radioactivity

Question 1

Beta Minus decay

Answer 1

A neutron becomes a proton and the atom releases and electron

Question 2

Beta Plus decay

Answer 2

A proton becomes a neutron and the atom releases a positron

Question 3

Alpha

Answer 3

An alpha particle is the equivalent to a helium nucleus

Question 4

Beta

Answer 4

A beta particle is an electron emitted from the nuclear

Question 5

Half life

Answer 5

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

Question 6

use of radioactivity

Answer 6

• smoke alarms
• sterilisation of equipment
• tracing and gauging thickness
• diagnosis and treatment of cancer
• Irradiating food

Question 7

What year did dalton say everything was made of atoms ?

Answer 7

1800

Question 8

What year did JJ Thomson discovered the electron?

Answer 8

1897

Question 9

What is the plum pudding model ?

Answer 9

The idea that the overall charge of an atom is neutral, so the negative electrons are dispersed through the positive pudding so the charges cancel out

Question 10

What year did Rutherford realise most of the atom was empty space ?

Answer 10

1911

Question 11

Who created the gold foil Experiment?

Answer 11

Hans Geiger and Ernest Marsden

Question 12

What is background radiation?

Answer 12

Radiation that is always present

Question 13

What is a source of background radiation ?

Answer 13

Nuclear weapon testing

Question 14

How do measure background radiation?

Answer 14

Geiger Müller counter or a photographic film

Question 15

How does the Geiger muller tube work ?

Answer 15

What the tube absorbs radiation it produces a pulse which is counted to count the amounts of radiation

Question 16

What will block beta radiation?

Answer 16

A thin sheet of aluminium

Question 17

What will block gamma radiation?

Answer 17

Several centimetres of lead

Question 18

What type of radiation is most ionising ?

Answer 18

Alpha

Question 19

Which type of radiation is least ionising?

Answer 19

Gamma

Question 20

What is the step to Rutherford model ?

Answer 20

1. Alpha particles were fired at a sheet of gold metal
2. most particles went straight through
3. Some particles were deflected

Question 21

What happens to an atom when alpha decay occurs ?

Answer 21

The atomic number decreases by 2
The mass number decreases by 4

Question 22

What does beta minus decay do to the atomic mass and number of an atom ?

Answer 22

The mass number stays unchanged
The atomic number increases by 1

Question 23

What are some examples of radioactivity uses ?

Answer 23

Smoke alarms
Irradiated food
Sterilisation of equipment
Treating and diagnosing cancer

Question 24

How do the smoke alarm work ?

Answer 24

1. The radioactive substance in the alarm emits alpha radiation
2. The alpha particles ionises the air in the detector (causing a current between plates)
3. When smoke interferes with the radiation the air is no longer ionised (the current between plates stop)
4. The reduction of flow triggers alarm

Question 25

What are 2 uses of nuclear radiation in the field of medicine ?

Answer 25

Examining internal organs and treatment of cancer

Question 26

Why is ionising radiation dangerous

Answer 26

It can cause cell mutation

Question 27

What precautions should people take when using ionising radiation?

Answer 27

Avoid handling the source directly
Wear radiation protection clothing
Use lead containers to reduce radiation escape

Question 28

How is a radioactive tracer used in medicine ?

Answer 28

1. The tracer is injected into the body
2. The tracer releases gamma radiation which is detected by a detector
3. The can be used to cheat a picture of patient body