Question

As you move from left to right on the periodic table, what generally happens to the electronegativity?

• A. It decreases
• B. It remains constant
• C. It decreases, then increases in the last column
• D. It increases, then decreases in the last column
• E. It increases

Answer 1

Answer: (E)

It increases

• From left to right across a period of elements, electronegativity increases. If the valence shell of an atom is less than half full, it requires less energy to lose an electron than to gain one. Conversely, if the valence shell is more than half full, it is easier to pull an electron into the valence shell than to donate one.
• From top to bottom down a group, electronegativity decreases. This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.