Unit 1, Topic 3: Bonding and Structure

Question 1

Describe how ions and ionic bonds are formed [4]

Answer 1

1. Ionic bonding occurs when elements gain or lose electrons
2. This forms positive and negative ions
3. These ions attract each other due to ‘strong’ net, non directional, electrostatic forces of attraction - the ionic bond
4. The ions are arranged in a 3D giant lattice

Question 2

Describe how ionic radii changes across the period [3]

Answer 2

• the radii decreases across the period for metal ions
• there is an increase for the anions
• as the positive charge of the nucleus increases and there are more electrons in the same shell, there is more attraction towards the nucleus

Question 3

Draw dot and cross diagrams for H2S, PH3, PF3, SCl2, AsF5, and HCN

Answer 3

LOOK IN ONENOTE

Question 4

Define ‘ionic bonding’

Answer 4

strong electrostatic attraction forces between positive ions of metals and negative ions of non metals

Question 5

Describe the shape of ionic crystals

Answer 5

a giant lattice of ions

Question 6

How can the strength of ionic bonding be measured?

Answer 6

the amount of energy needed to separate one mole of solid ionic compounds into gaseous ions

Question 7

What are the factors that affect the strength of an ionic bond [2]

Answer 7

1. ionic charge
2. ionic radius

Question 8

Explain how the ionic charge affects ionic strength [2]

Answer 8

• the larger the charge of the ion, the greater the ionic strength
• higher charge = stronger attraction

Question 9

Explain how the ionic radius affects ionic strength []

Answer 9

• the smaller the size of the radius, the stronger the ionic strength
• smaller ion –> packed in lattice closer to nucleus