How do i calculate the number of bond pairs and lone pairs in CH4 (Methane) and NH3 (Ammonia). Explain it please...

in CH₄ , valence electrons of carbon are 4 , it forms 4 bonds by sharing 1 electron with each hydrogen...

now all four electrons are utilised in sharing so no electron is left ...

lone pair(pair of non bonding electron) = 0

in NH₃ , valence electrons of N are 5  , 3 electrons are shared with 3 hydrogen so total electrons

remaining with N are 2 ...

lone pair = 1

total number of bonds = bond paires

for NH₃ , bond pairs = 3

for CH₄ , bond pairs = 4