Physical - Electronegativity

Question 1

Electronegativity

Answer 1

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

Question 2

Two elements that have similar electronegativity

Answer 2

will form a covalent
bond

Question 3

Two elements that have very different electronegativity

Answer 3

will form an ionic bond.

One atom attracts the pair of electrons so much that they gain the
electrons to form a negative ion.
* The other atom has lost electrons and forms a positive ion

Question 4

Are metals or non metals more electronegative

Answer 4

non
metals are more
electronegative
than metals

Question 5

There are three factors affecting electronegativity:

Answer 5

-Nuclear charge
* Shielding
* Atomic radius

Shielding outweighs all

Question 6

Nuclear charge

Answer 6

The more protons the element has, the greater the nuclear charge, the
stronger the attraction between the nucleus and the bonding pair of
electrons.

Question 7

Shielding

Answer 7

The nucleus attracts the electrons however electrons repel each other.

This means full electron shells shield the
bonding pair of electrons from the attraction of nucleus.

Question 8

The more electron shells,

Answer 8

the greater the
shielding effect. This means there is a weaker
attraction between the nucleus and the pair of
electrons in the covalent bond i.e. less
electronegative

Question 9

Atomic radius

Answer 9

The further away the shared pair of electrons are from the nucleus the more weakly they are attracted
to the nucleus and therefore less electronegative

Question 10

What factors might affect atomic radius?
*

Answer 10

Nuclear charge – the higher the nuclear charge the stronger the attraction between
nucleus and outer shell electrons therefore they are held closer
* Shielding – the more shielding there is the weaker the attraction between the nucleus
and outer shell electrons therefore they are held further away

Question 11

Explain why atomic radius decreases across a period

Answer 11

• Outer electrons are in same
  shell
• There is the same amount of
  shielding
• More protons in nucleus
• So stronger attraction
  between nucleus and outer
  shell electrons
• So outer shell electrons pulled
  closer to nucleus
• Atomic radius decreases

Question 12

The atomic radius increases down a group.

Answer 12

• Outer electrons are in a shell
  further away from the nucleus
• More shielding
• So weaker attraction between
  nucleus and outer shell
  electrons
• The outershell electrons move
  further away from the nucleus
• Atomic radius increase

Question 13

Electronegativity increases
across a period

Answer 13

• Atomic radius decreases
• Nuclear charge increases
• Same shielding
• ∴ Greater attraction between
  nucleus and bonding pair of
  electro

Question 14

Electronegativity decreases
down the group
*

Answer 14

Atomic radius increases
* Nuclear charge increase
* More shielding
* ∴ Less attraction between nucleus
and bonding pair of electrons