GCSE Questions - Electromagnetic Spectrum

Q1. A headline from a recent magazine article is shown below.

(a) Complete the following sentence. Skin cancer can be caused by exposure to excess_ _ _ _ _ _ _ _ rays from the Sun. (1 mark)

(b) Sunscreen should be used to protect your skin from the damaging effects of the Sun. A thick layer of sunscreen should be applied 30 minutes before sunbathing and re-applied every hour. The protection factor of a sunscreen lets you work out roughly how long you can stay in the Sun without causing damage to your skin. For example, a 'factor 10' sunscreen lets you stay in the Sun for up to ten times longer than if you were not using the sunscreen.

(i) Without sunscreen, a person with fair skin has found that she gets sunburn after 12 minutes of sunbathing. What is the maximum time that she could sunbathe without burning if she used 'factor 30' sunscreen on her skin? (1 mark)

(ii) Why does the protection factor give only a rough idea of how long you can sunbathe without getting sunburn? (1 mark)

(iii) Another person has naturally dark skin. Suggest why he can sunbathe with less risk of getting skin cancer than a fair-skinned person. (2 marks)

(c) Most people know that sunbathing can cause skin cancer. But most holidaymakers still
like to come home with a suntan.
Why is it important that people understand that there are dangers involved in sunbathing? (1 mark)

(Total 6 marks)