The electronic configuration 2,8,2 shows that there are 2 valance electrons in the outermost shell hence it belongs to group two and it has 3 shells (K, L, M) thus belongs to period three.
The Group Number tells us the number of valance electrons
The Period Number tell us the number of shells
M is magnesium (2,8,2) with atomic number 12.
The chemical formula of the compounds formed are:
(i) Mg2+ + NO3-→ Mg (NO3)2 (magnesium nitrate)
(ii) Mg2+ + SO42-→ Mg (SO4)(magnesium sulphate)
(iii) Mg2+ + PO43-→ Mg3 (PO4)2 (magnesium phosphate)
‘M’ will form ionic compounds by losing two valence electrons to achieve a noble gas configuration, that is, a stable octet in the valence shell.
Rate this question :