The penultimate shell of Francium (Z = 87) has the configuration

The managanese (Z = 25) has the outer configuration.

In the penultimate shells, correct configur-ations of group 14 elements

Ca^(2+) is more stable than Zn^(2+) because Ca^(2+) has _____ configuration in valency shell where as Zn^(2+) has pseudooctet configuration in valency shell.

Which of the following compound (S) has Z-configuration?