2.9 Skin Care

Question 1

Ultraviolet radiation

Answer 1

Ultraviolet radiation (UV) is a high-energy form of light, present in sunlight. UV light can provide sufficient energy to break bonds within molecules. This causes sunburn and accelerates ageing of the skin. Sun-block products prevent UV light reaching the skin.

Question 2

Free radicals

Answer 2

Free radicals are atoms or molecules that are highly reactive due to the presence of unpaired electrons.

Question 3

how are free radicals formed?

Answer 3

When UV light breaks bonds, free radicals are formed

Question 4

free radical chain reaction steps

Answer 4

1. initiation
2. propagation
3. termination

Question 5

free radical scavengers

Answer 5

Free radical scavengers are molecules that react with free radicals to form stable molecules and prevent chain reactions from occurring. Free radical scavengers are added to many products including cosmetics, food products and plastics.