Stabileste valenta elementelor dupa formulele: a) NH3, PH3, CH4. b) SO3, P2O3, c)N2O, NO, N2O3

Răspuns :

a) N-valenta 3; H-valenta1
P-valenta 3; H-valenta 1
C-valenta 4; H-valenta 1
b)S-valenta 6; O-valenta 2
P-valenta 3; O-valenta 2
c)N-valenta 1; O-valenta 2
N- valenta 2; o- valenta 2
N-valenta 3; O-valenta 2.