Oxygen is more electronegative than chlorine because of the following reasons : In periodic table locate the position of oxygen and chlorine, with respect to fluorine. Oxygen is placed towards the left side of fluorine so has one electron less than fluorine.

TREND OF ELECTRONEGATIVITY IN A PERIODIC TABLE (ACROSS A PERIOD) Generally, electronegativity of an element increases while we move from left to right across a period in the periodic table of elements.

The electronegativity trend refers to a trend that can be seen across the periodic table. This trend is seen as you move across the periodic table from left to right: the electronegativity increases while it decreases as you move down a group of elements.

Check out boron: it’s less electronegative than hydrogen [2.0 vs….Carbon is More Electronegative Than You Think.

Why is chlorine more electronegative than carbon? Because of valance shell configuration differences between two elements. Chlorine has 7 which need s only one electron to fulfill eight in valance shell. In contrast carbon has needs 4.

Polar Covalent Bonds

In general, elements with the most negative electron affinities (the highest affinity for an added electron) are those with the smallest size and highest ionization energies and are located in the upper right corner of the periodic table.