a)
stim ca Ar = (c1xA1+c2A2+...+cnAn)/100
= (64x48,63+27,93x66+4,10x67+18,75x68+0,60x70)/100
= 65,47 u.a.m.
b)
1 mol Zn .......... 65 g Zn ..................... 6,022x10la23 atomi
x g ............................ 1,8066x10la24 atomi
= 19,5 g Zn
c)
Zn are Z = 30
1s2 2s2 2p6 3s2 3p6 4s2 3d10 => 12e pe ultimul strat
=> 1 mol Zn ................... 12x6,022x10la23 e- pe ultimul strat
= 7,224x10la24 e-