Răspuns:
Explicație:
a.
10 g Ca
n= 10g : 40g/moli= 0,25 moli de atomi de Ca
1mol Ca ------6,023.10²³ atomi Ca
0,25 moli Ca------------x
x= 0,25 . 6,023 .10²³ atomi Ca
b.
n= 12,7 g : 127g/moli= 0,1moli de atomi de iod
1mol de atomi de iod---------6,023.10²³ atomi iod
0,1 moli---------------------------------x
x= 0,1 . 6,023.10²³atomi iod =
c.
1mol de atomi Pb-----------6,023.10²³atomi Pb
0,5 moli ---------------------------------x
x= 0.5 . 6,023.10²³atomi Pb =
d.
1mol de atomi Zn-----------6,023.10²³atomi Zn
0,25 moli---------------------------------x
x= 0,25 . 6,023 .10²³atomiu Zn =
