ELECTRONEGATIVITY
Electronegativity is a concept which is used to help understand
which atom in a chemical bond will have the greatest attraction
for the bonding pair of electrons. Electronegativity is a measure
of the ability of an atom in a chemical bond to attract electrons
to itself.
From the figure one can see the important trend in
electronegativity across a period and down a group. In general
the electronegativity increases going across a period, and
decreases going down a group.