Respuesta :

peridorito8864
The 3 indicates the third electron shell. (Which has only 1 electron in it in this configuration)

Hope this helps! :)
InesWalston

Answer: option A

Explanation: since as we know that notation to write electronic configuration is nl^x

Here n represents the main shell number and l tells about subshell and X denotes the no of Electrons present in that subshell.

In our case , n=3 ,that means it t main third shell. Or we can say it as shell 'M'