Answer:
from left to right, bottom to top
Explanation:
Ionization energy increases from left to right across a period and from bottom to top in a group.
As you move across a period, the size of the atom decreases. The outer electrons are closer to the nucleus and more strongly attracted to the center, making it more difficult to remove the outermost electron.
As you move up a group, electrons are closer to the nucleus making it more difficult to remove the outermost one.
Hope that helps.
