Halogen is a group of nonmetallic elements consisting of fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts) /Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_17%3A_The_Halogens/0Group_17%3A_Physical_Properties_of_the_Halogens/Group_17%3A_General_Properties_of_Halogens). The name halogen comes from the Greek roots hal- (“salt”) and -gen (“to produce”), because they all produce sodium salts of similar properties, of which sodium chloride—table salt, or halite—is best known. Halogens are highly reactive and do not exist in elemental form in nature. They are found in the environment only in the form of ions or compounds because of their high reactivity. The halogens can combine with other elements to form compounds known as halides—namely, fluorides, chlorides, bromides, iodides, and astatides. The halogens show great resemblances to one another in their general chemical behavior and in the properties of their compounds with other elements. Some of the physical and chemical properties of halogens are:
Physical Properties:
- The group of halogens is the only periodic table group that contains elements in all three familiar states of matter at standard temperature and pressure.
- Fluorine (F) is a pale yellow gas.
- Chlorine (Cl) is a greenish gas.
- Bromine (Br) is a dark red liquid.
- Iodine (I) is a black solid, and when heated, it forms a purple vapor.
- Astatine (At) is a black solid.
- The halogens have a strong and often nasty smell.
- The halogen elements are extremely toxic.
- They are poor conductors of heat and electricity.
- Low melting and boiling points.
Chemical Properties:
- Molecules of all halogens are homonuclear diatomic/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_17%3A_The_Halogens/0Group_17%3A_Physical_Properties_of_the_Halogens/Group_17%3A_General_Properties_of_Halogens).
- Halogens are highly reactive and can form different compounds such as halides, interhalogens, and polyhalogenated compounds.
- Halogens act as oxidizing agents and exhibit the property to oxidize metals/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_17%3A_The_Halogens/0Group_17%3A_Physical_Properties_of_the_Halogens/Group_17%3A_General_Properties_of_Halogens).
- When in the -1 oxidation state, with carbon or nitrogen in organic compounds, the halogens often form single bonds/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_17%3A_The_Halogens/0Group_17%3A_Physical_Properties_of_the_Halogens/Group_17%3A_General_Properties_of_Halogens).
- Halogen elements can cross-link to form diatomic molecules with polar covalent single bonds/Descriptive_Chemistry/Elements_Organized_by_Block...
