Q1
Dear Student
In Lithium, the removal of electron takes places from 2s1 configuration thereby leading to 1s2 configuration which is extremely stable whereas when an electron is removed from boron, then the configuration changes from 2p1 to 1s2 2s2 which is less stable as compared to that of Lithium. Thus, First Ionisation Enthalpy of Lithium is more stable and smaller than that of Beryllium.
In case of Second Ionisation Enthalpy, removal of electron from 1s2 of Lithium becomes difficult as the electrons are tighly bound to the nucleus, also Li has a small size as compared to that of Be. Therefore, Second Ionisation Enthalpy of Li is much greater than that of Beryllium.
Regards
In Lithium, the removal of electron takes places from 2s1 configuration thereby leading to 1s2 configuration which is extremely stable whereas when an electron is removed from boron, then the configuration changes from 2p1 to 1s2 2s2 which is less stable as compared to that of Lithium. Thus, First Ionisation Enthalpy of Lithium is more stable and smaller than that of Beryllium.
In case of Second Ionisation Enthalpy, removal of electron from 1s2 of Lithium becomes difficult as the electrons are tighly bound to the nucleus, also Li has a small size as compared to that of Be. Therefore, Second Ionisation Enthalpy of Li is much greater than that of Beryllium.
Regards