bonding & structure

Question 1

explain why sodium oxide has a high melting point

Answer 1

• giant ionic structure
• strong electrostatic forces of attractions between oppositely charged ions
• require a lots of energy to overcome forces

Question 2

explain why alloys are harder than pure metals

Answer 2

• atoms are different sizes
• distorts the layers
• making it harder to slide over each other

Question 3

why would you not expect titanium chloride to be a liquid at room temp?

Answer 3

• metal chlorides usually form ionic bonds
• so have high melting points
• as strong electrostatic forces between ions
• which require a lot of energy to overcome

Question 4

explain how the structure of graphene makes it useful in electronics

Answer 4

• each C covalently bonded to 3 other leaving 1 free electron
• is delocalised so can move through structure carrying charge
• so can conduct efficiently and is very thin and flexible due to one layer

Question 5

describe how bonding in iron allows it to conduct

Answer 5

• metal atoms arranged in regular layers
• delocalised electrons present through metallic structure
• electrons free to move
• free-moving delocalised electrons can carry charge