For 1st group, the order for mobility is Rb+>K+>Na+>Li+ Ionic mobility is inversely proportional to hydration enthalpy. Further hydration enthalpy is inversely proportional to size of the ion. Hence ionic mobility is maximum for Rubidium ion.

The composition of gypsum is CaS04. 2H20, while others are carbonates.  

Beryllium shows anomalous properties with alkaline earth metals, due to its small size.

Freons are Chlorofluorocarbon compounds that contain only carbon, chlorine, and fluorine.

Only the compounds containing peptide bonds gives positive biuret test. Only two compounds Glycylalanine( contains a peptide bond between two amino acid ) and tripeptide( contains two peptide bonds between three amino acids ) gives positive Biuret test. Therefore 2 compounds gives ...Read more