Question

How do you write a Lewis structure for `CH_3NH_3^+`?

Answer 1

Count up the valence electrons............

Explanation:

And that is `6` from the hydrogens, `5` from the nitrogen, and `4` from the carbon, i.e. `15`, from which subtract `1` to account for the positive charge on the ammonium centre. We are left with `14` electrons, or `7` electron pairs, to distibute across the central carbon and nitrogen centres.

`H_3C-N^(+)H_3`. Here, there are `3xxC-H` bonds, `1xxC-N` bond, and `3xxN-H` bonds, i.e. 7 electron pairs AS REQUIRED.

Can you do same for `CH_4` and `NH_4^+`?