Question

How do electronegativity values change across a row?

Answer 1

Across a Periodic Row from left to right as we face the Table, electronegativity should increase.

Explanation:

Electronegativity is conceived to be the ability of an atom in a chemical bond to polarize electron density towards itself. There are various scales of which the Pauling scale was the earliest, and still th one that is most widely used.

Discounting the Noble Gases (which after all do not tend to form chemical bonds), given the above definition, we would expect the `"Group VII halogens"` and `"Group VI chalcogens"` to be the most electronegative atoms, and indeed we would be correct. `F` and `O`, which head the Group, are the most electronegative atoms.