Răspuns:
A,Al=27g/mol N,A= 6,022X10²³at/mol
1mol Al.........27g.............6,022x10²³at
2mol...............x......................y
x= m=54g A
y= 12,044x10²³at F
A,O=16g/mol
1mol atomiO..........16g............6,022X10²³at
0,25mol...................x...................y
x= 4g A
y=1,50x10²³at A
A,Ca=40g/mol
1mol..............40g
x......................8g
x=0,2mol A
xplicație: