1. OZONE DEPLETION

3. ELECTROMAGNETIC SPECTRUM

5. TYPES OF UV RADIATION UV – A (AGING): Low energy.
Thought to contribute to premature aging and wrinkling of the skin and has recently been implicated as a cause of skin cancer. 
 UV – B (BURNING):
Medium energy.
UVB is more dangerous than UVA and has been implicated as a major cause of skin cancers, sunburning and cataracts. 
 UV – C:
High energy.
UVC is extremely dangerous but does not reach the earth’s surface due to absorption in the atmosphere.  Most of the radiation below 290 nm is absorbed by the ozone in the upper atmosphere.  Depletion of this layer increases the amount of UVC reaching ground level.
TYPES OF UV RADIATION

6. OZONE LAYER DECREASES…. INCREASED UV RADIATION ENTERS
HEALTH

9. Impacts on environmental systems
Decreased primary productivity (land & ocean)
Damage to fish/amphibians / mammals
Disrupt food chain
Effects on food crops (beans, wheat, rice, corn)
Impacts on environmental systems

11. ATMOSPHRE LAB

12. Cumulative Graph should look like…

13. Ozone Depletion Ozone- molecule consisting of 3 oxygen atoms
Benefit to humans because it absorbs harmful UV radiation
Ozone layer is being depleted because of the addition of chemicals (esp. CFC’s) that break apart the ozone molecule
Ozone Video (2:20)
Guided notes consideration: explain how CFC’s interact with ozone; describe the changes in the “hole”

15. CHEMICAL CLASSES OF OZONE DESTROYERS
CHLOROFLOUROCARBONS
(CFC'S)
HALOCARBONS/HALONS
(ODS)
No significant natural sources identified
Source: Air conditioning, Aerosol propellants, solvents, styrofoam
GREAT longevity
takes 5-7 years for CFC’s to go from ground to upper atm.
Highly reactive group 17
Cl, Br, F
Sources: Styrofoam, Solvents, Soil Fumigant, Fire Extinguishers

18. OZONE PHLEMISTRY WKST

19. NATURAL O3 becomes O2 NATURALO2 becomes O3 O3 + UV  O2 + ●O
3) ●O + ●O  O2
NATURALO2 becomes O3
O2 + UV  ●O + ●O
2) O2 + ●O  O3
2 Ozone become 3 Oxygen
CFCs degrades O3 into O2
CCl2F2 + UV  ●CClF2 + ●Cl
2) ●Cl + O3  ClO● + O2
NO degrades O3 into O2
1) NO + O3  NO2 + O2
Airplanes!

20. OZONE CHEMISTRY for the visual learners

21. STEP 1: NATURAL FORMATION OF OXYGEN

22. STEP 2: Natural Formation of Ozone in the Stratosphere
UV ENERGY
3 OXYGEN MOLECULES
2 OXYGEN RADICALS
2 OZONE MOLECULES

23. Step 3: Natural Breakdown of Ozone in the STRATOSPHERE

24. CFC’s BREAKING DOWN OZONE (anthropogenic causes)
STEP 4:
(anthropogenic causes)
CFC
Free Radical
Chlorine
OZONE
CLO*
OXYGEN
Free Radical
Oxygen
Free Radical
Chlorine
PER CHLORINE ATOM BROKEN OFF BY UV RADIATION FROM CFC’S, ,000 OZONE MOLECULES CAN BE BROKEN DOWN
(~900,000 O3 MOLEUCLES PER CFC!)

27. Antarctic Ozone Hole (16 min) Ozzy Ozone (10 min)
Ozone over Antarctica
Antarctic Ozone Hole (16 min) Ozzy Ozone (10 min)
See word document- standard: use Ozzy; honors: choose either; MY: Antarctic Ozone Hole
Both videos will be a quicktime file found on the I drive

28. THOMAS MIDGLEY