Răspuns:
a)
Z=12 Mg 1s2 2s2 2p6 3s2
Z=35 Br 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
b)Z=12 Mg 1s2 2s2 2p6 3s2 -2e→ 1s2 2s2 2p6
Z=35 Br 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 +1e→Z=35 Br 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6
c) .. . .
Mg: + 2:Br:----> Mg²⁺ + 2:Br: ⁻---> MgBr2
d) MMgBr2=24+2×80=184g/mol
184gMgBr2..........................24gMg......................160gBr
100gMgBr.............................xgMg........................ygBr
x=100×24/184=calculeaza
y=100×160/184/ calculeaza
. . .
Explicație: