How many valence electrons do group one have?

1 Answer
Aug 9, 2016

Answer:

Explanation:

Group I elements have one valence electron on their outer shell. This is the main reason why their are placed in group I.

Let us take a look on the electron configuration on some of these elements:

#""_1H: 1s^1#
#""_3Li: 1s^(2)2s^(1)#
#""_11Na: 1s^(2)2s^(2)2p^(6)3s^(1)#
#""_19K: 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)#
#""_37Rb: 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(10)4p^(6)5s^(1)#

As you can notice, the electron configuration of all these elements end with #color(blue)(n)s^(color(red)(1))#, where #color(blue)(n)# represents the outer shell, and the number #color(red)(1)# indicates that there is only one valence electron in these elements.