Electronegativity & Polar Covalent Bonds

Question 1

What is electronegativity?

Answer 1

The power of an atom to attract the electron density in a covalent bond.

Question 2

What happens to electronegativity when you increase nuclear charge?

Answer 2

It increases

Question 3

What happens to electronegativity when you increase Atomic Radius?

Answer 3

As increasing the atomic radius increases the shielding in the atom, this decreases electronegativity.

Question 4

What is the trend in electronegativity across a period?

Answer 4

As electrons are going into the same energy level, but the nuclear charge is increasing, the electrons are more attracted to the nucleus reducing the atomic radius and hence increasing the electronegativity.

Question 5

What is the trend in electronegativity up the group?

Answer 5

There are fewer energy levels in use and the outer electrons are less shielded and are increasingly attracted to the nucleus so the atomic radius is decreases and so electronegativity increases.

Question 6

What is a polar molecule?

Answer 6

One which the electron density across the whole molecule is unevenly distributed (not symmetrical)