2. Halogens a.k.a Barbarians

3. Iodine 53 Protons 74 Neutrons 53 Electrons

4. About Iodine Atomic Number: 53 Atomic Symbol: I Atomic Weight: 126.9045 Atomic Radius: 133.3 pm Melting Point: 113.7 degrees C Boiling Point: 184.4 degrees C

5. More About Iodine  Discovered by Courtois in 1811  Can be obtained from the reaction of potassium iodine with copper sulfate  A bluish-black, lustrous solid  Very useful in medicine  Important in organic chemistry

6. Bromine Nucleus: 35 Protons 45 Neutrons 35 Electrons

7. About Bromine oAtomic Number: 35 oAtomic Symbol: Br oAtomic Weight: 79.904 oAtomic Radius: 115 pm oMelting Point: -7.2 degrees C oBoiling Point: 58.8 degrees C

8. More About Bromine  Discovered by Balard in 1826  Obtained from natural brines from wells in Michigan and Arkansas  The only nonmetallic liquid element  It is a heavy, mobile, reddish-brown liquid  Used in fumigants, flame proofing agents, water purification compounds, dyes, medicines, sanitizers, and more

9. Chlorine 17 Protons 18 Neutrons 17 Electrons

10. About Chlorine  Atomic Number: 17  Atomic Symbol: Cl  Atomic Weight: 35.453  Atomic Radius: 99 pm  Melting Point: -101.5 degrees C  Boiling Point: -34.4 degrees C

11. More About Chlorine DDiscovered in 1774 by Scheele, who thought it contained oxygen. NNamed in 1810 by Davy, he insisted it was an element IIn nature it is found in the combined state only IIt is a greenish-yellow gas UUsed in making everyday products, like making safe drinking water

12. Fluorine 9 Protons 10 Neutrons 9 Electrons

13. About Fluorine  Atomic Number: 9  Atomic Symbol: F  Atomic Weight: 18.998403  Atomic Radius: 70.9 pm  Melting Point: -219.67 degrees C  Boiling Point: -188.12 degrees C

14. More About Fluorine  After 74 years of continuous effort, fluorine was finally isolated in 1866 by Moissan  It is a pale yellow gas  Used in producing uranium  In small amounts it helps prevent dental cavities

15. Sources http://pearl1.lanl.gov/external/default.htm