Răspuns:
n=nr. moli ; m=masa subst. ( g) ; M=masa molara(g/moli )
Explicație:
a.
n=m : M
n= 270g : 27g/moli= 10 moli Al
1mol de atomi de Al------------6,023.10²³atomi Al
10 moli Al------------------------------x
x=10 . 6,023.10²³=60,023 . 10²³ atomi de Al
b.
n= 23g : 23g/moli= 1mol Na
1mol de atomi de Na------------6,023.10²³atomi de Na
c.
n=112g : 56g/moli=2 moli Fe
1mol de atomi de Fe-----------------6,023.10²³atomi Fe
2moli--------------------------------------------x
x= 2 . 6,023.10²³=12,046 .10²³atomi Fe
d.
n= 124g : 31g/moli= 4moli fosfor
1mol de atomi de P-------------------6,023.10²³atomi P
4moli --------------------------------------------x
x= 4 . 6,023.10²³=24,092 .10²³atomi fosfor
e.
n=120g : 24g/moli= 5 moli Mg
1mol Mg---------------------6,023.10²³ atomi Mg
5moli--------------------------------x
x= 5 . 6,023.10²³=30,115 .10²³atomi Mg
f.
n= 80g : 40g/moli=2moli Ca
1molCa--------------------6,023.10²³ atomi Ca
2moli--------------------------x
x= 2 . 6,023.10²³=12, 046 .10²³atomi Ca
g.
n=260g : 65g/moli=4moli Zn
1mol Zn-------------------6,023.10²³Zn
4moli----------------------------x
x=4 . 6,023.10²³=24,092.10²³ atomi de Zn
h.
pentru 78 g K lucreaza singur , sa vezi daca ai inteles
i.
n=220g : 55g/moli=4moli Mn
1molMn-----------------6,023.10²³Mn
4moli--------------------------x
x=4 . 6,023.10²³ =24,092.10²³atomi Mn
j.
n= 40g : 4g/moli=10 moli He
1mol He-----------6,023.10²³He
10 moli------------------------x
x=10 .6,023.10²³= 60,023.10²³atomi He
