The alkali earth metals have the smallest first ionization energies.
Helium has the highest first ionization energy and francium has the lowest first ionization energy.
One can recognize a periodic trend on the periodic table by observing properties of different elements from the left side to the right side of the periodic table.
Barium(Ba)
magnesium (Mg)
question: which of the following elements is the smallest?
answer: chlorine (CI)
The electronegativity is the ability to loss electrons.
For example this is a salt.