Question

Which of the following properties of the elements of group 2nd (alkaline earth metals) does not increase with increasing atomic number

• A. Stability of carbonate
• B. Solubility of hydroxide
• C. Reactivity with water
• D. First ionization energy

Answer 1

Answer: (D)

First ionization energy

Answer 2

(1) The thermal stability of oxy-acid salts of alkaline earth metals generally increases down the group with increasing metallic character, i.e. electropositive character.

(2) The solublility of the alkaline earth metal hydroxides increases down the group from Be to Ba. This is because of the fact that down the group with increasing size of cation the lattice energy as well as hydration energy also decrease but the change in lattice energy is more as compare to that of hydration energy.

(3) Down the group atomic size increases and, therefore, attraction between the valence shell electron and nucleus decreases ; so ionisation enthalpy decreases. Hence, they react with water with increasing vigour even in cold to form hydroxides from Be to Ba