2.2.10 Electronegativty and Bond Polarity

Question 1

What is electronegativity?

Answer 1

The ability of an atom to attract the bonding electrons in a covalent bond.

Question 2

What scale can we use to measure electronegativity?

Answer 2

The Pauling scale.

Question 3

What is atomic radius?

Answer 3

The distance between the outer electrons in the outermost shell and the nucleus.

Question 4

How does atomic radius affect electronegativity?

Answer 4

If you decrease atomic radius, electronegativity increases. The shorter the distance between the negative outer electrons and the positive nucleus, the stronger the attraction between them.

Question 5

What is nuclear charge also known as?

Answer 5

The number of protons in the nucleus.

Question 6

How does nuclear charge affect electronegativity?

Answer 6

If the number of protons is increases, then the nuclear attraction towards the outer electrons also increases. The negatively charged electrons and positively charged protons are attracted to each other.

Question 7

How does shielding affect electronegativity?

Answer 7

If you increase the number of subshells and inner shells of an atom, the electronegativity decreases. This is because the electrons of the inner shells ‘shield’ the outer electrons from the attraction of the nucleus, causing the attraction between the outer electrons and the nucleus to decrease.

Question 8

When might dipoles of any bonds within a molecule cancel out?

Answer 8

If the molecule is symmetrical.

Question 9

What is a permanent dipole?

Answer 9

A small charge difference across a bond that results from a difference in the electronegativities of the bonded atoms.