Setting of plaster of Paris is
dehydration
oxidation with atmospheric oxygen
combination with atmospheric CO2
hydration to yield another hydrate
The set representing the right order of ionic radius is
Li+ > Na+> Mg2+ > Be2+
Mg2+ > Be2+> Li+> Na+
Na+> Mg2+> Li+> Be+
Na+> Li+> Mg2+> Be+
Atomic radius (pm) of Al, Si,N and F respectively is:
117, 143, 64, 74
143, 117, 74, 64
143, 47, 64, 74
64, 74, 117, 143
B.
143, 117, 74, 64
Al, Si belong to 3rd period of periodic table while N, and fluorine to second periods. The size of element decreases from left to right in a period hence the order of size is:
Al> Si> N> F.
The correct order of hydration enthalpies of alkali metal ions is:
Li+ > Na+ > K+ > Cs+ > Rb+
Na+ > Li+ > K+ > Rb+ > Cs+
Na+ > Li+ > K+ > Cs+ > Rb+
Li+ > Na+ > K+ > Rb+ > Cs+
The isoelectronic set of ions is :
Li+, Na+, O2- and F-
N3-, O2-, F- and Na+
F-, Li+, Na+ and Mg2+
N3-,Li+, Mg2+ and O2-