1 / 17

Halogens

Halogens. Group 7A (Group 17). “halogen”. Halos- salt Gen- “genesis”, to form SALT FORMERS. All halogens…. Have 7 electrons in their valence shell Have an oxidation number of -1 Exist, at room temperature, in all three phases of matter Form diatomic molecules. Diatomic molecules.

ethel
Download Presentation

Halogens

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Halogens Group 7A (Group 17)

  2. “halogen” • Halos- salt • Gen- “genesis”, to form • SALT FORMERS

  3. All halogens… • Have 7 electrons in their valence shell • Have an oxidation number of -1 • Exist, at room temperature, in all three phases of matter • Form diatomic molecules

  4. Diatomic molecules • A molecule consisting of two atoms • F2, Cl2, Br2, I2, At2

  5. fluorine • Atomic Number 9 • Gas at room temperature • F • Toothpaste- NaF • Pale, yellow gas • Fluere- “to flow” • In presence of H, burns with reactive force

  6. chlorine • Atomic number 17 • Poisonous, yellow-green gas • Cl • Bleach • PVC • DDT • HCl • CCl4

  7. bromine • Atomic number 35 • Liquid at room temperature • Br • Manufacture of photographic film • Thick, reddish-brown fumes when exposed to air • Bromos- “stench” • Chlorinated water with brackish water

  8. iodine • Atomic number 53 • Solid at room temperature • I • Iodes- “violet-colored” • Seaweed and brine wells • Poison • “tincture of iodine”- antiseptic • Important dietary supplement • I-131 half-life 8.1 days

  9. astatine • Atomic number 85 • Solid at room temperature • 20 radioactive isotopes • At-210 (t1/2=8.3 hrs) • Astatos- “unstable” • 1 millionth of 1 gram produced artifically

  10. Noble Gases Group 8A Group (18)

  11. Noble gases • Considered completely inert until 1960 • Oxidation number of 0

  12. helium • Atomic number 2 • He • 2nd to Hydrogen in universe • Found in natural gas and results from radioactive decay • Very low density • US stockpiles • He-Ne laser in supermarkets

  13. neon • Atomic number 10 • Ne • Neos- “new” • 5th most common element in atmosphere (.002%) • 1898- Sir William Ramsay

  14. argon • Atomic number 18 • Ar • Colorless and odorless • 1% of earth’s atmosphere • Argos- “lazy and inactive” • Commercially obtained by distillation of liquid air • Incandescent light bulbs • Potassium-argon dating

  15. krypton • Atomic number 36 • Kr • KrF4 (1966) • Krytos- “hidden” • Trace amounts in air • Odorless, colorless, tasteless, harmless • Pale purple- airport runway and approach lights

  16. xenon • Atomic number 54 • Xe • Density 5x air • Xenos- “the strange one” • Forms some compounds • Rapidly flashing strobe lights

  17. radon • Atomic number 86 • Rn • 20 known radioactive isotopes • Radon-222 (t1/2= 3.82 days) • Tobacco- radon, uranium, lead: 1,000x greater than those working in nuclear power plants

More Related