Răspuns:
Explicație:
n= m : M ; n=nr.moli ; m=masa subst.( g) ;M=masa molara(g/moli)
n=160g : 40g/moli=4moli Ca
1mol Ca ----------6,023.10²³ atomi Ca
4moli ------------------x
x= 4. 6,023.10²³atomi=24,092 .10²³atomi Ca
n= 18,066 .10²³ : 6,023 .10²³=3moli Si
m= 3moli . 28g/moli = 84g Si