Question

(a) The list below shows energy sources used by power stations, to generate electricity.

                      coal                        gas                       hydroelectric (HEP)

                                   nuclear                       petroleum

(i) State the three energy sources from the list that produce carbon dioxide when generating  electricity.
1 ……………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………….
3 ……………………………………………………………………………………………………………………….

(ii) Coal is described as a non-renewable energy source.
Explain what is meant by non-renewable when describing an energy source.

………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….

(iii) State one disadvantage of using nuclear fuel to generate electricity.

………………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………. 
(b) (i) In a nuclear power station, fission of plutonium-239 nuclei takes place.
Describe what happens to the nucleus of a plutonium-239 atom during nuclear fission.
……………………………………………………………………………………………………………………. 

(ii) State a safe way of storing a small sample of radioactive material.

………………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………. 
(c) Technetium-99 is a radioactive material. The half-life of technetium-99 is 6 hours.
Calculate the percentage of technetium-99 remaining in a sample after 24 hours.

                                                                                 percentage = ……………………………………………..

▶️Answer/Explanation

Ans:  3(a)(i) any two from:
             coal
             gas
             petroleum ;;

3(a)(ii) only existing as a finite quantity / being used up at a faster rate than it can be replaced ; 
3(a)(iii) nuclear accidents / nuclear / dangerous / harmful waste produced ; 
3(b)(i) (nucleus) splits ; 
3(b)(ii) in a lead lined container ; 
3(c) 4 half-lives / division by 16 ;
       6.25% ;