n Ar(H)

w = --------

     M(HNO3)

M(HNO3)=63г/моль

w(H)=1/63 =0,02

w(N)=14/63=0.22

w(O)=48/63=0.76

w = (Ar(E)*n/Mr)*100%

w(H)= (1/63)*100% = 1.6 %

w(N) = (14/63)*100% = 22.2 %

w(O) = (16*3/63)*100% = 76.2 %

Ответ:   1.6 %,  22.2 %,  76.2 %.