Unit 2 Skin Care

Question 1

What is ultra violet(UV) radiation?

Answer 1

High energy form of light, present in sunlight

Question 2

What are the effects of UV radiation?

Answer 2

Extensive exposure to UV radiation in sunlight can have damage effects on skin
UV radiation can break bonds within a molecule resulting in formation of free radicals

Question 3

How do u prevent skin damage by UV?

Answer 3

Sunblock-blocks UV light from reaching skin

Question 4

What are free radicals?

Answer 4

Are highly reactive, unstable molecules due to unpaired electron

Question 5

What are the steps of free radical chain reaction?

Answer 5

Initiation
Breaking bonds by UV to form free radicals
Propagation
Free radical colliding with a stable molecule to reform a covalent bond resulting in formation of another free radical
Termination
Free radical colliding with another free radical forming a stable molecule and ending free radical chain reaction

Question 6

What are the equations of each steps?

Answer 6

Initiation
Cl2 - Cl• + Cl•

Propagation
Cl2 + H• - HCl + Cl•
H2 + Cl• - HCl + H•

Termination
H• + H• - H2
H• + Cl• - HCl
Cl• + Cl• - Cl2

Question 7

What are free radical scavengers?

Answer 7

Molecules that react with free radicals to form a stable molecule preventing chain reaction