Question -
Answer -
The 1st ionizationenthalpy of magnesium is higher than 1st ionization enthalpy ofsodium because,
- Magnesium is having greater atomic size than sodium.
- Magnesium is having higher effective nuclear charge than sodium.
Thus, energy requiredto expel an electron from sodium is lower than that in magnesium. Thus, the 1st ionizationenthalpy of magnesium is higher than 1st ionization enthalpy ofsodium.
The 2nd ionizationenthalpy of magnesium is lower than 2nd ionization enthalpy ofsodium is because after expelling an electron, there is still 1 electronremaining in the 3s-orbital of magnesium, whereas sodium achieves stable inertgas configuration after expelling an electron. So, magnesium still requires toexpel 1 electron to achieve stable inert gas configuration.
Thus, energy requiredto expel 2nd electron from magnesium is lower than that insodium. Thus, the 2nd ionization enthalpy of magnesium is lowerthan 2nd ionization enthalpy of sodium.