3.4 Electronegativity - bond polarity in covalent bonds

Question 1

Define electronegativity

Answer 1

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

Question 2

Define electron density

Answer 2

The way the negative charge is distributed in a molecule

Question 3

How is electronegativity measured? When is it higher?

Answer 3

The Pauling scale (0-4)
- the greater the no., the greater the electronegativity

Question 4

Factors that affect electronegativity

Answer 4

• nuclear charge
• atomic radius (nucleus to outer shell)
• e- shielding

Question 5

Trend in electronegativity down a group

Answer 5

Decreases
- more e- shielding
- atoms get bigger
- same nuclear charge

Question 6

Trend in electronegativity across a period

Answer 6

Increases
- nuclear charge increases
- same e- shielding

Question 7

Where is the most electronegative? What atoms is it?

Answer 7

Top right-hand corner
-fluorine

Question 8

What is polarity of covalent bonds?

Answer 8

The unequal sharing of electrons between covalently bonded atons

Question 9

Polarity in covalent bonds between two of the same atom

Answer 9

Non-polar
- e- shared equally
- same electronegativity
- symmetrical

Question 10

Polarity in covalent bonds between two different atoms

Answer 10

The greater the electronegativity difference, the greater the polarity of the covalent bond