# Question #796c2

Feb 4, 2016

#### Explanation:

Each column (which chemists call 'group') will have elements having the same valency. They have the same number of electrons in their outermost shell.

Some examples of common elements with $n$ valence electrons

$n = 1$ - Li, Na, K
$n = 2$ - Be, Mg, Ca
$n = 3$ - B, Al
$n = 4$ - C, Si
$n = 5$ - N, P
$n = 6$ - O, Si
$n = 7$ - F, Cl, Br, I
$n = 8$ - He, Ne, Ar