Question

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

Answer 1

Electronegativity is the property of the element to attract electrons to its nucleus. The trend of electronegativity in the periodic table is decreasing from right to left and decreasing from top to bottom. hence from the given elements, the element with the highest electronegativity should be A.beryllium 

Answer 2

Answer: 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.