Question

The property of the alkaline earth metals which increases with their atomic number is:

• A. ionisation energy
• B. electronegativity
• C. solubility of their hydroxides in water
• D. solubility of their sulphates in water

Answer 1

Answer: (C)

solubility of their hydroxides in water

Ionization energy decreases as the atomic number increases. It is because of an increase in atomic size due to addition of new shells and an increase in the magnitude of screening effect of the electrons in inner shells.

The electronegativities decreases as the atomic number increases.

The solubility of the alkaline earth metal hydroxides increases with increase in atomic number due to the decrease in lattice energy on moving down the group.

Hence, option $C$ is correct.