Răspuns:
a)
MP=31g/mol
n=m/M=50/31=1,6mol P
1mol P..................6,022x10²³atomi
1,6moliP.....................x atomi
x=1,6x6,022x10²³atomi/1=calcuelaza
b)
MCu=64g/mol
n=m/M=20/64=0,3moli Cu
1mol Cu..................6,022x10²³atomi
0,3moliCu....................y atomi
y=0,3x6,022x10²³atomi/1=calculeaza
Explicație: