Write Lewis structure for the following
(a) Ethene `(C_(2)H_(4))` the most important reactant in polymer manufacture
(b) Nitrogen `(N_(2))` the most abundant atmosheric gas
(c ) Methanol `(CH_(4)O)` an important industrial alcohol that is begin used as a gasoline alternative in car engines .

Explanation

Step:1 Place the atoms relative to each other. The H atoms can have only one bond, so C and O must be adjacent to each other. In nearly all their compounds, C has four bonds and O has two, so we arrange the H atoms to shown this.
Step : 2 Find sum of valence electrons
`[1xx C (4e ^(-)) ] + [1xxO (6e ^(-)) ] + [ 4 xx H (1e ^(-)) ] = 14 e ^(-) {:(" "H),(H " "C " "O " "H),(" "H):}`
Step :3 Add single bonds and subtract `2e^(-)` for each bond. `H- underset(H) underset(|) overset(H) overset(|) (C) -O-H`
Five bonds ue `10 e^(-), so 14 e ^(-)- 10 e ^(-)` leaves `4e ^(-)` remaining.
Step :4 Add remaining electrons in pairs.

Carbond already has an octet, so the four remaining velence `e ^(-)` from two lone pairs on O and give the Lewis strructure for methanol.