Answer:
The elements described above are halogens present in 17 group.
Explanation:
The elements of group 17 are called halogens. These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. Halogens are very reactive these elements can not be found free in nature. They have seven valance electrons. Their chemical properties are resemble greatly with each other. As we move down the group in periodic table size of halogens increases that's way fluorine is smaller in size as compared to other halogens elements. Their boiling points also increases down the group which changes their physical states. i.e fluorine is gas while iodine is solid. They have low melting point and boiling point.
Fluorine:
1. it is yellow in color.
2. it is flammable gas.
3. it is highly corrosive.
4. fluorine has pungent smell.
5. its reactions with all other elements are very vigorous except neon, oxygen, krypton and helium.
Chlorine:
1. it is greenish-yellow irritating gas.
2. its melting point is 172.2 K
3. its boiling point is 238.6 K
4. it is disinfectant and can kill the bacteria.
5. it is also used in manufacturing of paper, paints and textile industries.
Iodine:
1. it is present in solid form.
2. it is crystalline in nature.
3. it is very corrosive and has pungent odor.
4. it can not react with oxygen and nitrogen.
