Question

If your periodic table does not display the electronegativity value, how can you deduce the difference in electronegativity between two elements?

Answer 1

Trend-wise, as one moves from left to right across a period in the periodic table, the electronegativity increases due to the stronger attraction that the atoms obtain as the nuclear charge increases. Moving down a group, the electronegativity decreases due to the longer distance between the nucleus and the valence electron shell, thereby decreasing the attraction, making the atom have less of an attraction for electrons or protons.
Source: http://en.wikipedia.org/wiki/Periodic_trends