The Halogen's - Group 7
Chlorine is a green yellow gas which combines directly with nearly all elements. Chlorine is a respiratory irritant. The gas irritates the mucous membranes and the liquid burns the skin. Chlorine was used as a war gas in 1915.Chlorine can be found in swimming pools. And chlorine can also be found in seawater where it is called sodium chloride.
Bromine is the only liquid non-metallic element. It is a reddish-brown liquid. The red vapour has a strong unpleasant odour and the vapour irritates the eyes and throat. It is a bleaching. When spilled on the skin it produces painful sores. It is a serious health hazard, and maximum safety precautions should be taken. Bromine can found in bleach.
Fluorine is a Group 17 element. Fluorine is the most electronegative and reactive of all elements. It is a yellow, corrosive gas, which reacts with practically all organic and inorganic substances. Finely divided metals, glass, carbon, and even water burn in fluorine with a bright flame. Fluorine can be used for, dental products such as toothpaste, rocket fuel and municipal water supplies.