Electronegativity

Question 1

Define Electronegativity:

Answer 1

A measure of the power an atom has to attract the electrons in a covalent bond towards itself

Question 2

Electronegativity increases…

Answer 2

…as you go along (left to right) and up the periodic table

Question 3

What is the most electronegative element?

Answer 3

Fluorine

Question 4

Electronegativity depends on: (3 things)

Answer 4

1. Nuclear Charge 2. Size of the atom 3.Shielding

Question 5

How does ‘nuclear charge’ affect electronegativity?

Answer 5

(nuclear charge depends on the number of protons in the nucleus)

• the more protons in the nucleus
• the more positive charge
• therefore the stronger attration between the nucleus and the negative charge (electrons)

Question 6

How does the ‘size of an atom’ affect electronegativity?

Answer 6

• the atom is smaller
• therefore the nucleus is closer to the shared electrons
• so theres greater electronegativity

Question 7

How does ‘shielding’ affect electronegativity of an atom?

Answer 7

• the larger the nuclear charge the greater the shielding effect
• therefore theres greater electronegativity

-

• same energy level = same shielding
• only levels closer to the nucleus affect shielding

Question 8

What does this diagram show?

Answer 8

A and B have the same electronegativity

Question 9

What does the term ‘same electronegativity’ mean?

Answer 9

• both elements have the same tendancy to attract bonding pairs of electrons
• on average the electrons are found half way between the atoms
• the atoms would be of the same element, e.g. H₂

Question 10

What does this diagram show?

Answer 10

• The atoms have different electronegativity
• B is slightly more negative than A