Question

How do you calculate electronegativity of compounds?

Answer 1

Electronegativity, symbol $X$, measures the tendency of an atom to attract a shared pair of electrons (or electron density).[1] An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons.

Complete step-by-step answer:
Electronegativity is conceived to be the capability of an atom in a molecule to polarize or attract electron density towards itself. Here conceived is written because there is nothing fundamental about term electronegativity, and measurement and the measurement of electronegativity depends on various ad hoc. Scales,of which the Pauling scale is the most famous and still widely used.

It makes sense that the most electronegative atoms, $F$ and $O$ are the ones that are in right-most in the Periodic Table. For a given Period as Z, the as atomic number increases, effective nuclear charge increases and the valence electrons are held more tightly as more protons are added to the atomic nucleus this is demonstrated in the marked decrease in atomic radii across a Period.

Note: The opposite of electronegativity is electropositivity: a measure of an element's ability to donate electrons. An element whose electrode potential is more positive than that of the standard hydrogen electrode which is assigned an arbitrary value of zero. Electropositive elements tend to lose electrons and form positive ions, e.g. the univalent alkali metals $L{i^ + }$, $N{a^ + }$, ${K^ + }$, etc., and the divalent alkaline-earth metals $B{e^{ + 2}}$, $M{g^{ + 2}}$, $C{a^{ + 2}}$.