Unit 3 - Skin Care

Question 1

Ultraviolet Radiation

Answer 1

Ultraviolet (UV) radiation is a high-energy form of light, present in sunlight. UV light can provide sufficient energy to break bonds within molecules (causing sunburn, ageing skin and cancer)

This is an example of a free radical reaction.

Question 2

Free Radical Reactions

Answer 2

When UV light breaks bonds, free radicals are formed. Free radicals are atoms or molecules that are extremely unstable and therefore highly reactive due to the presence of unpaired electrons

Question 3

Steps of Free Radical Chain Reactions

Answer 3

Free radical chain reactions include the following steps: initiation, propagation and
termination.

Question 4

Free Radical Scavengers

Answer 4

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

Question 5

Example of Free Radical Scavenger

Answer 5

Vitamin C