1. Conversations with the Earth Tom Burbine tburbine@framingham.edu

2. Midterm March 24 Covers everything including Tuesday-Wednesday class You can bring in a sheet of paper with anything written on it You can bring in your hand-written mineral sheets

3. Review Session Wednesday evening at 4:30 pm in Hemenway 229

5. Radiation dosage 1 rad = 0.01 J of radiant energy absorbed by kilogram of tissue Rem = rads x Q where Q is a quality factor which attempts to convert rads from different types of radioactivity into a common scale of biological damage. Lethal dose is 400-450 Rem

6. Some types of radiation Alpha particle – 2 protons and 2 neutrons (Helium nucleus) –Do not normally penetrate clothing –High kinetic energy (due to high mass) ; can damage living tissue Beta particle – electron (from a neutron when it becomes a proton) –Penetrate clothing and into skin Gamma ray - High-frequency radiation –Penetrate into skin and can damage molecules in cells

8. http://www.darvill.clara.net/nucrad/types.htm

10. Isotope half-life 232 U 68.9 y 233 U 159,200 yr 234 U 245,500 yr 235 U 7.038×10 8 yr 236 U 2.342×10 7 yr 238 U 4.468×10 9 yr

14. Iodine-131, the radioactive form of iodine, is absorbed by the thyroid and can cause thyroid cancer. Half-life of 8 days Cesium-137, which isn’t stored in any one part of the body, increases the overall cancer risk by as much as a few percentage points. Half-life of 30 years

19. Meltdown – melting of the core of a nuclear reactor

20. http://abcnews.go.com/watch/world-news-with- diane-sawyer/SH5585921/VD55117252/world- news-311-disaster-in-the-pacific-japan- earthquake?rfr=googlehttp://abcnews.go.com/watch/world-news-with- diane-sawyer/SH5585921/VD55117252/world- news-311-disaster-in-the-pacific-japan- earthquake?rfr=google

21. Any Questions?