Q.
The first ionisation enthalpy of Na, Mg and Si are 496, 737, 776 kJ/mol respectively. What will be the first ionisation enthalpy potential of AI in kJ/mol?
3480
236
AIIMSAIIMS 2013Classification of Elements and Periodicity in Properties
Report Error
Solution:
Na,Mg,Al and Si are in period 3andas we move across the period, the atomic size decreases and hence ionisation enthalpy increases. So, the order is Na<Mg<Al<Si Hence, IE of Al is greater than that of Mg (737kJ/mol) and lower than that of Si (776kJ/mol)