Question

a Draw a Lewis structure for CH_4 Explicitly draw all H atoms. Include all valence lone pairs in your answer. Include all nonzero formal charges. C opy P aste H ** H н. H H

Answer 1

Answer : The Lewis-dot structure of
`CH_4` is shown below.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The given molecule is,
`CH_4`

As we know that carbon has '4' valence electrons and hydrogen has '1' valence electron.

Therefore, the total number of valence electrons in
`CH_4` = 4 + 4(1) = 8

According to Lewis-dot structure, there are 8 number of bonding electrons and 0 number of non-bonding electrons.

Now we have to determine the formal charge for each atom.

Formula for formal charge :

`\text{Formal charge}=\text{Valence electrons}-\text{Non-bonding electrons}-\frac{\text{Bonding electrons}}{2}`

`\text{Formal charge on C}=4-0-(8)/(2)=0`

`\text{Formal charge on }H_1=1-0-(2)/(2)=0`

`\text{Formal charge on }H_2=1-0-(2)/(2)=0`

`\text{Formal charge on }H_3=1-0-(2)/(2)=0`

`\text{Formal charge on }H_4=1-0-(2)/(2)=0`

Hence, the Lewis-dot structure of
`CH_4` is shown below.