Răspuns:
Explicație:
NH3
r.a.= 1 : 3
r.m.= 14 : 3
M= 14 + 3=17--------> 17g/moli
comp. proc. prin masa moleculara
17 g NH3---------------14g N-------------3g H
100 g NH3-----------------x-------------------y
x= 100 . 14 : 17=82,35 % N
y= 100 . 3 : 17=17,65% H
