Which of the following is the correct order of ionisation enthalpy ?

Options

A. `Te^(2-) lt I^(-) lt Cs^(+) lt Ba^(2+)`
B. `I^(-) ltTe^(2-) lt Cs^(+) lt Ba^(2+)`
C. `Te^(2-) lt Cs^(+) lt I^(-) lt Ba^(2+)`
D. `Ba^(2+) lt Cs^(+) lt I^(-) lt Te^(2-)`

Answer

1

Explanation

All are isoelectronic species but as number of protons i.e. atomic number increases, the attraction between electron ( to be removed ) and nucleus increases and thus ionisation enthalpies increase.
Order of `A:Te^(2-)(52) lt l^(-)(53) lt Cs^(+)(55) lt Ba^(2+)(56)` . So same will be the order of IE.