Halogens

1. Halogens By: Ethan Weber and Michael Viggiano

2. HALOGENS • Halogens are group 17 on the periodic table. • The halogen group consists of chlorine, fluorine, iodine and astatine. • They are the most reactive elements of the non-metals. • None of the halogens occur freely in nature.

3. Fluorine • At room temperature fluorine is a poisonous, pale yellow gas. • Fluorine is also the most reactive element in the halogen group. • Fluorine is also used in our water supply at 1 part/million to prevent tooth decay. • The first known usage of fluorine was in 1670.

4. Chlorine • At room temperature chlorine is a pale green, poisonous gas. • It does not occur freely in nature and is usually found in sea water and table salt. • In liquid form chlorine burns the skin. • In WWI chlorine was used in biological warfare because in gas form it irritates the nose and eyes and can cause blinding. • Chlorine is commonly used in pools to kill bacteria and pathogens in the water.

5. Bromine • At room temperature bromine is a smelly reddish-brown liquid. • Bromine is extremely toxic and caustic and in gas form irritates the nose, eyes and throat. • Bromine was discovered in 1826 by Carl Löwe. • Bromine is named after the Latin word for smelly, bromos.

6. Iodine • Iodine is a bluish-black solid at room temperature. • Iodine is the least reactive element out of the halogen group. • Iodine is essential to human life and iodine deficiency in the body is dangerous. • Iodine is mostly found in the ocean and is absorbed from seaweed.

7. Astatine • Astatine does not occur in nature and has to be synthetically produced. • Astatine is extremely radioactive and the longest lasting isotope (At210) only has a half life of 8.3 hours.