Predict where the largest jump between successive ionization energies occurs for Sr .

Answer 1

Looking at the electron configuration for Sr we have ...

[Kr]5s2

So IE1 is to remove the first 5s electron ->[Kr]5s1

IE2 is to remove the 2nd 5s electron -> [Kr]

IE3 would be a big jump because you are trying to remove an electron from the noble gas configuration which is very stable. So, the answer would be IE3 would be the largest jump.