Lesson 5 - Detecting Nuclear Radiation

Question 1

What type of radiation is most ionising?

Answer 1

Alpha

Question 2

What radiation is most penetrating?

Answer 2

gamma

Question 3

What type of radiation is the least ionising?

Answer 3

Gamma

Question 4

What radiation is the most penetrating?

Answer 4

Alpha

Question 5

What is the name of the instrument that helps you detect radiation?

Answer 5

Geiger-Muller Tube and Counter

Question 6

How does the geiger-muller counter and tube work?

Answer 6

Radiation causes ionisation.

lost electron produces electrical current in the Geiger muller tube

A click is then produced.

Question 7

How does photographic film help detect radiation?

Answer 7

When radiation hits the photographic film, it turns from white to black Attach the badge to someone’s clothes and we can monitor how quickly the film turns black. A worker in a nuclear powerstation may use this to monitor how much radiation they are exposed to.

The plastic case will block alpha. The thin aluminium sheet will stop beta Lead will stop all (alpha, beta, gamma)
Thin aluminium window will block beta and alpha

Question 8

Why is photographic film used by people?

Answer 8

It helps control teh amount of radiation that people come in contact with. This is by if the photographic film becomes too black, then the person would be sent back away from the radiation place.

Question 9

When a Geiger counter is left in a classroom, it may click. Why?

Answer 9

Background radiation makes it click.

Question 10

What is background radiation?

Answer 10

Radiation that is not part is not part of the experiment.

Question 11

Examples of background radiation.

Answer 11

Chair, table, etc.

Question 12

what is natural background radiation?

Answer 12

Radiation from things that are not made from humans

Question 13

Examples of background radiation.

Answer 13

Rocks, soil, air

Question 14

What is artificial background radiation?

Answer 14

Radiation that is from things that are created by humans

Question 15

Examples for artificial background radiation.

Answer 15

School, cars, hospitals

Question 16

How do you determine if the radioactive source in front of a Geiger-muller tube is releasing alpha, beta or gamma?

Answer 16

●Place the radio active source in front of the geiger counter at a set distance.
● Record the number of counts (activity) in 1minute.
●Then add a piece of paper in between the geiger counter and source. If there is a significant decrease in the count rate (How quickly the counts rise) , the source emits alpha.
●If not, replace the thin sheet with a thin sheet of aluminium. Significant decrease means its beta, otherwise it is gamma.
●Replacing the thin sheet of aluminium with lead should cause the count rate to stop increasing as all radiation should be blocked.

Question 17

How can you ensure that you account for the background radiation?

Answer 17

Turn the geiger counter on for the same time as one experiment. (E.g. 1 minute)
Record the amount of radiation detected from the surrounding subtract the background counts from the results you get