Radioactivity - Atomic Structure Physics

Question 1

What is used to detect radioactive decay?

Answer 1

Geiger-Muller tubes

Question 2

What happens to an object that has been exposed to ionisation?

Answer 2

It is irradiated not radioactive

Question 3

What is radioactive contamination?

Answer 3

Unwanted presence of materials containing radioactive atoms on other materials

Question 4

What can ionisation do to a living cell?

Answer 4

Damage/kill a cell

Question 5

Which radiation is more dangerous to the body?

Answer 5

Alpha radiation because it has the highest ionising power

Question 6

State 3 ways to reduce ionising exposure

Answer 6

• Keeping far away
• Spending little time in environements that are ionising
• Shielding - thick concrete barriers

Question 7

Explain how Ruthford observations support that the alpha particles deflected

Answer 7

Most of the mass and charge are concentrated in the nucleas.

Question 8

Explain how Ruthford observations support that the alpha particles went straight through

Answer 8

The particle was mostly of empty space

Question 9

Suggest one way our bodeis are radioactive

Answer 9

Becuase of the food we eat

Question 10

Why is a radioactive source kept in a lead box?

Answer 10

Lead absorbs the radiation

Question 11

Why isnt gamma radiation affected by magnets?

Answer 11

Gamma radiation has no charge so it doesn’t deflect. It isn’t affected

Question 12

Why is gamma radiation used in a radioactive tracer?

Answer 12

• Less ionising
• Less dangerous

Question 13

6 reasons why scientists keep a scientific journal for their findings

Answer 13

• Newspapers distort the facts,
• It has to be peer reviewed before being published
• becomes part of the scientific record
• other sicentists can develop or include their work
• one of the ways communities of scientists find out whats going on in their field
• establishes their research as credible in the eyes of their peers and the public

Question 14

Explain how the distance at which an electron orbits the nucleas may be changed.

Answer 14

Electrons may absorb electromagnetic radiation and move further from the nucleas to a high energy level.

Question 15

Energy level which are further from the nucleus are at a ________ than those which are closer to the nucleus

Answer 15

high energy

Question 16

Where does background radiation come from?

Answer 16

Naturally occurring unstable isotopes like food, rocks, buildings
Radiation from space - cosmic rays from Sun, earth’s atmosphere protects us from it
Human activity - nuclear explosions and waste

Question 17

How can you prevent contamination?

Answer 17

Gloves and tongs and protective suits

Question 18

What sources are more dangerous outside the body and why?

Answer 18

Beta and gamma , highly penetrating and can damage organs

Question 19

Which source is the most dangerous inside the body and why?

Answer 19

Alpha, highly ionising and they do all their damage is a very localised area

Question 20

What does a short half life mean?

Answer 20

Activity falls quickly cuz nuclei are v unstable and rapidly decay, they are dangerous cuz of the high amount of radiation they emit at spread start but they quickly become safe

Question 21

What does a long half life mean?

Answer 21

Activity falls more slowly cuz most of the nuclei don’t decay for a long time, source releases small amounts of radiation for a long time, can be dangerous cuz nearby areas exposed to this for millions

Question 22

what is radioactive decay

Answer 22

isotopes with unstable nucleus give out radiation to become stable

Question 23

what is activity? units?

Answer 23

rate at which a source of unstable nuclei decay in becquerel (Bq)