Bond polarity

Question 1

electronegativity definition

Answer 1

the power of an atom to attract the pair of electrons in a covalent bond

Question 2

what 3 factors affect the electronegativity of an atom?

Answer 2

• nuclear charge
• atomic radius
• shielding

Question 3

how does electronegativity change down a group?

Answer 3

decreases down a group

Question 4

how does electronegativity change across a period?

Answer 4

increases across a period

Question 5

when does a polar covalent bond exist?

Answer 5

when the two atoms in a covalent bond have a different electronegativity

Question 6

when is a covalent bond non-polar?

Answer 6

when the two atoms have the same electronegativity

Question 7

what is a polar covalent bond? what happens?

Answer 7

covalent bond where the two electrons are not shared equally- the more electronegative atom has a greater share of the two electrons and the less electronegative atom has a lower share

Question 8

what is a bond dipole moment?

Answer 8

a measure of the strength and direction of the polarity in a bond - the bigger the difference in electronegativity, the bigger the bond dipole moment

Question 9

what type of bonds have a bond dipole moment?

Answer 9

covalent bonds that are polar have a bond dipole moment

Question 10

example of a polar molecule

Answer 10

Question 11

does a molecule that contains polar bonds have to be polar?

Answer 11

no - if the molecule is symmetrical, the dipole moments cancel each other out and the molecule has no overall polarity