Răspuns:
miu,NH3=17g/mol
niu=m/miu=85/17mol= 5mol
1mol molec...........N,A molec
5molmolec..............x= 5NA molecule
1molecula ......(7+3x1) e
5NA----------------X
X= 10X5x6,022X10²³ e==301x10²³ e
Explicație: