20 POINTS!!! A part of the periodic table is shown.
A portion of the first two columns of the periodic table is shown. Column one from top to bottom reads three lithium, 11 sodium, and 19 potassium. Column two reads four beryllium, 12 magnesium, and 20 calcium.
Which of the following elements is less reactive than the others?
Beryllium (Be)
Calcium (Ca)
Lithium (Li)
Magnesium (Mg)