Question

Account for the fact that there is a decrease in first ionization enthalpy from Be to B and Mg to Al.

Answer 1

Answer:

First Ionisation Enthalpy : B‹Be

First Ionisation Enthalpy : B‹Be Al‹Mg

Explanation:

B = 1s²2s²2p¹

Be=1s²2s²

Here , Be is stable Therefore It has Higher Ionisation Enthalpy.

Similarly,

Al = 1s²2s²2p6 3s²3p¹

Mg= 1s²2s²2p6 3s²

Mg is more stable than Al so that It has Higher Ionisation Enthalpy.