halogens in environment

Question 1

ozone layer

Answer 1

outer edge of earth stratosphere
absorbs UV-B radiation from sun rays

Question 2

effects of ozone depletion

Answer 2

increased skin/ genetic damage
greater risk of skin cancer

Question 3

effect of UV

Answer 3

breaks C-H bond by homolytic fission to form radicals

Question 4

photodissociation

Answer 4

radiation initiating break down

Question 5

break down of ozone

Answer 5

Propagation 1: Cl* + O3 → ClO* + O2
Propagation 2: ClO* + O→ Cl* + O2
Overall: O3
+ O → 2O2
chlorine radical may go on in chain reaction

Question 6

other radicals

Answer 6

NO formed by lightning strikes
NO* + O3 → NO2 * + O2
NO2* + O → NO* + O2
Overall O3
+ O → O2

Question 7

research into alternatives to CFCs

Answer 7

coolants using hydrocarbons, ammonia or CO2 produced

Question 8

organobromine problems

Answer 8

suspected to release toxins that may interfere with endocrine system in humans