How many valence electrons are in N2O? SeCl2? PBr3?

Here is the answer for the three of them

N20 = 16 e-

SeCl2 = 20

PBr3 = 26

Remember that t o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.