posted by Ashley .
Which of the following has the higher ionization energy and why: Li or Ba?
I cannot figure this out because they are in different periods but Ba is down on the periodic table telling me that it may have a higher ionization than Li. Help please?
I don't know that there is a way of knowing this. However, I would go with the idea that Li is so small and Ba so large that Ba has a smaller IP than Li. The electron for Ba is so far away from the nucleus it should be easier to pull it off when compared to Li whose outside electron is so close to the nucleus. You know most small periodic charts have a wealth of information on them. Mine lists the first IP of each element and shows Li as 5.39 and Ba as 5.21. Very close.
Thank you so much, this was extremely helpful for me to understand.