The elements found in group 2a, from top to bottom, include beryllium, magnesium, calcium, strontium, and barium. which of these elements has the highest electronegativity value? a. beryllium b. magnesium c. calcium d. barium

A. beryllium

Explanation: Electronegativity of an element is the tendency to attract the share pair of electron towards itself.

The electronegativity increases across a period as the size keeps decreasing, because the electrons get added to the same shell. the valence shell gets nearer to the nucleus and tendency to attract the shared pair of electron keeps increasing.

The electronegativity decreases as we move down a group as the size of the atom keeps increasing and the valence shell keeps moving away from the nucleus, so the incoming electron could not exert the nuclear charge effectively and hence the tendency to attract the shared pair of electron keeps decreasing.

"the periodic table is arranged in order of atomic number."