Răspuns:
Explicație:
a.
m= n . M
m= 3moli . 23g/moli= 69g Na
b.
3. 6,022 .10 ²³atomi C= 18 ,066 .10²³ atomi C
1mol de atomi de C ------------6,022.10²³atomi C
xmoli-------------------------------18,066 .10²³
x= 18,066 .10²³ : 6,022.10²³= 3 moli de atomi C
m= n . M
m= 3moli . 12g/moli = 36g C