4.2.1/2/3 Bonding, structure properties of matter (must know) PAPER 1 part 1

Question 1

Where do ionic bonds form

Answer 1

Metals combining with non-metals

Question 2

What happens in ionic bonding

Answer 2

Metal atoms lose outer shell electrons to form positive ions
Non metals gain electrons to form negative ions
The oppositely charged ions strongly attract each other

They do this to make their outer shells full, strong electrostatic attraction holds the ions together in the ionic compound

Question 3

How do you represent ionic bonding

Answer 3

Dot and cross diagrams

Draw square brackets around each ion with a positive or negative charge next to it

Question 4

Limitations of dot and cross diagrams (ionic)

Answer 4

They don’t show the structure of the compound
Don’t show how the ions are arranged
Don’t show the relative sizes

Question 5

Structure of ionic compounds

Answer 5

They have a giant lattice structure of oppositely charged ions
Strong electrostatic forces of attraction between oppositely charged ions hold the ions in the giant lattice
The forces act in all directions

Question 6

Limitations of ball and stick models (ionic)

Answer 6

The ions are not shown close together, when in fact they are

The lines linking the ions should not be there as they are used to represent covalent bonds between non-metals only

Question 7

Limitations of 3D models (ionic)

Answer 7

They only let you see the outer layer of the compound

Question 8

Physical properties of ionic compounds + explanation

Answer 8

High mtp - A lot of energy needed to break strong ionic bonds throughout the giant lattice
Conducts electricity when melted or dissolved - Ions are NOT held in a giant lattice so free to move and carry charge
Does not conduct electricity when solid - Ions are held in giant lattice not free to move and carry charge

Question 9

What is covalent bonding between

Answer 9

A non metal and a non metal

Question 10

What is covalent bonding

Answer 10

When a pair of electrons are shared between 2 atoms
They do this to get full outer shells

Covalent bonds have very strong electrostatic forces

Question 11

Limitations of dot and cross diagrams (covalent)

Answer 11

Doesn’t show the electrons moving

Question 12

Limitations of ball and stick models (covalent)

Answer 12

They don’t show where the electrons in the bonds have come from
They can get confusing for large molecules

Question 13

Physical properties of molecules

Answer 13

Low mtp/bpt - little energy needed to break weak intermolecular forces in molecular structure
Do not conduct electricity - No ions or free electrons to carry charge