# The number of halogens known as so far is

$\begin{array}{1 1}4\\5\\6\\7\end{array}$

The halogens are a group in the periodic table consisting of five chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
The number of halogens known as so far is 5
edited Nov 24, 2017