Group+17Hr2

The Halogen Group Flourine, Iodine, Chlorine, Bromine, and Astatine

 Atomic #: 9 Atomic Mass: 19 Protons: 9 Neutrons: 10 Electrons: 9 Fluorine: is the most electronegative and reactive of all elements. It is a pale yellow, corrosive gas, which reacts with practically all organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame. It is not uncommon to see fluorine spelled incorrectly as flourine. 
 * __Fluorine:__**

__**Chlorine:**__ Atomic #: 17 Atomic Mass: 35 Protons: 17 Neutrons: 18 Electrons: 17 Chlorine: is a greenish yellow gas which combines directly with nearly all elements. Chlorine is a respiratory irritant. The gas irritates the mucus membranes and the liquid burns the skin. As little as 3.5 parts per million can be detected as an odor, and 1000ppm is likely to be fatal after a few deep breaths. It was used as a war gas in 1915. It is not found in a free state in nature, but is found commonly as NaCl (solid or seawater).

__**Bromine:**__ Atomic #: 35 Atomic Mass: 80 Protons: 35 Neutrons: 45 Electrons: 35 Bromine: is the only liquid non-metallic element. It is a member of the Halogen group. It's a heavy, volatile, mobile, dangerous reddish-brown liquid. The red vapor has a strong unpleasant odor and the vapor irritates the eyes and throat. When spilled on the skin it produces painful sores. It is a serious health hazard, and maximum safety precautions should be taken when handling it.

__**Iodine:**__ Atomic #: 53 Atomic Mass: 127 Protons: 53 Neutrons: 74 Electrons: 53 Iodine: is a bluish-black, lustrous solid. It volatilizes at ambient temperatures into a pretty blue-violet gas with an irritating odor. It is less reactive then the other elements in this group. It displays metallic like properties. Iodine compounds are important in organic chemistry and very useful in medicine and photography.

__**Astatine:**__ Atomic #: 85 Atomic Mass: 210 Protons: 85 Neutrons: 125 Electrons: 8 Astatine: is the longest-lived isotope, 210At, has a half-life of only 8.3 hours. There are about 20 isotopes known, all of which are radioactive. Astatine is a halogen and possibly accumulates in the thyroid like iodine. It is radioactive and not found in nature.

__**Quantum Numbers****:**__ Fluorine: n=2, l=1, m=0, m2=-½ Chlorine: n=3, l=1, m1=0, m2=-½ Bromine: n=4, l=1, m1=0, m2=-½ Iodine: n=5, l=1, m1=0, m2=-½ Astatine: n=6, l=1, m1=0, m2=-½

__**Electron Configuration:**__ Fluorine: 1s²2s²2p⁵ Chlorine: 1s²2s²2p⁶3s²3p⁵ Bromine: 1s²2s²2p⁶3s²3p⁶4s²3d¹º4p⁵ Iodine: 1s²2s²2p⁶3s²3p⁶4s²3d¹º4p⁶5s²4d¹º5p⁵ Astatine: 1s²2s²2p⁶3s²3p⁶4s²3d¹º4p⁶5s²4d¹º5p⁶6s²4f¹⁴5d¹º6p⁵

1. Halogen means "salt forming". 2. Fluorine was discovered by Karl Scheele in 1771. 3. Chlorine was discovered by Sir Humphrey Davy in 1810. 4. Bromine was discovered by A.J. Balardin in 1826. 5. Iodine was discovered by Bernard Courtois in 1811. 6. Astatine was discovered by Dale R. Corson, K. R. MacKenzie, and Emilio Segre in 1940. __**Sources:**__ www.webelements.com www.funtrivia.com
 * __Fun Facts:__**