Question

"Moving down group 2A (Alkaline Earth Metals), which element has the largest first ionization energy?" Is the answer to this: Radium?

Also, could you explain what a "first" ionization energy is?

Thanks!

Answer 1

Ionization energy is the energy it takes to remove the outermost electron of an element in the gaseous form. Generally, ionization energy decreases as you go down a group because it is easier to remove the valence electrons. It's easier to remove because the electrons are further away from the nucleus as there are more and more shells. Electrons from previous shells block some of the pull of the nucleus for the valence electrons. This is called the "shielding effect."

If ionization energy decreases as you go down a group, the top element in group 2A, which is Beryllium, should have the highest.

Answer 2

Wow! Thanks so much, Rogue! That was the exact answer I was looking for. I appreciate your detailed response.

Answer 3

Your welcome =) If you take AP chem later or are taking AP chem, you'll learn this and much more ;)

Answer 4

Sounds good - thanks! :)