S3 Physics Radioactivity 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

1. What effects can radiation have on living cells? answer Change the nature of cells Kill cells  

Sterilising surgical instruments Killing cancerous cells . 2 Give two examples of radiation being used in medicine to kill cells.     answer Sterilising surgical instruments Killing cancerous cells  

3. What is the central part of the atom called? answer The nucleus

4. Name the particles orbiting around the nucleus. . answer Electrons  

5. Name the particles found in the nucleus. answer Protons and neutrons  

6. State the charge on the Electron Proton Neutron answer Negative Positive None

7. Name the three types of nuclear radiation. answer Alpha (α) Beta (β) Gamma (ϒ)

8. Which radiation has the shortest range in air? answer Alpha (α).

9. What types of radiation would not pass through a 5mm thick sheet of aluminium? answer Alpha (α) and Beta (β)  

Q10 What is meant by ionisation? answer The addition, or removal, of an electron from an uncharged atom.  

11. Some radiation detectors rely on ionisation. Name one such device answer Geiger-Muller tube  

12. Define Absorbed Dose of radiation. answer The energy transferred per kilogram of the absorbing material.  

13. State the unit of Absorbed Dose. answer Gray (Gy)

14. State 3 factors which determine the biological harm from exposure to radiation. answer The absorbed dose The type of radiation The body organs /tissue exposed  

15. What quantity measures the biological effect of radiation on human tissue?   answer Equivalent Dose (H)  

16. State the unit of Equivalent Dose. answer Sieverts (Sv)  

17. What is the name of the process in which a large nucleus splits into two smaller nuclei?   answer Nuclear Fission  

18. Name two types of nuclear fission answer Spontaneous fission Induced fission

Two “light” nuclei join together releasing energy. 19. Nuclear fusion takes place in the sun. Briefly describe what happens in this process. answer Two “light” nuclei join together releasing energy.

It could produce large amounts of relatively “clean” energy 20. Physicists are currently trying to produce Fusion reactions. How would success be of benefit to society? answer It could produce large amounts of relatively “clean” energy