Atomic structure

Easy

Which row contains two species with different numbers of electrons?

$CO\text{CO}$ and $CN−\text{CN}^-$

$H2S\text{H}_2\text{S}$ and $PH3\text{PH}_3$

$NH4+\text{NH}_4^+$ and $PH4+\text{PH}_4^+$

$CO2\text{CO}_2$ and $N2O\text{N}_2\text{O}$

Atomic structure Questions