Question 1:
Diagram 1 shows three radioactive radiations, P, Q and R.


(a) Name radioactive radiations P and R. [2 marks]

(b) State the charges of radioactive radiation P and Q.[2 marks]

(c) Name the substance that can stop the penetration of radioactive radiation R. [1 mark]

(d) Name the radioactive radiation which is used to kill cancer cells. [1 mark]


Answer:
(a)
P: Alpha radiation
R: Gamma radiation

(b)
P: Positively charged
Q: Negatively charged

(c) Thick block of lead or concrete.

(d) Gamma radiation

Question 2:
Diagram 2 shows the use of a radioactive substance in food preservation.


(a) State the function of gamma radiation in this process. [1 mark]

(b) State two uses of gamma radiation other than food preservation.[2 marks]

(c) Name one material which can stop gamma radiation. [1 mark]

(d) State two dangerous effects of gamma radiation to human beings. [2 marks]


Answer:
(a) To kill microorganisms in the potatoes without changing their taste and appearance.

(b)
- To kill cancerous cells
- To control the thickness of paper, plastic or metal
- To kill or sterilize pests
(any two)

(c) Lead which is a few centimetres thick

(d)
- Kills body cells
- Causes cancer
- Causes mutation
(any two)