The halogens are found in Group 17 of the periodic table. This group includes the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
Halogens are known for their reactivity and are commonly found in nature as diatomic molecules. They have seven valence electrons, which means they are one electron short of having a full outer shell. This makes them eager to gain an additional electron during chemical reactions, leading to their high reactivity.
The properties of halogens can vary significantly from one element to another. For example, fluorine is a pale yellow gas at room temperature, while iodine appears as a dark purple solid. Despite these differences, they all share similar chemical properties due to their position in the periodic table.