sarea se scrie Na2CO3
miu(M)=(2X23gNa+12gC+3x16gO)/mol=106g/mol
niu,mol= m/miu; niu= 288g/106g/mol=2,7mol
1mol sare..........2molatomi Na
2,7mol.................n=5,4mol atomiNa
1mol atomi....are.....6,023x10²³atomi
5,4mol......................N= 5,4x6,023x10²³atomi=....................calculeaza !!!!!