covalent structures

Question 1

explain the solid structures of simple molecular lattices

Answer 1

consist of covalently bonded molecules held together by london forces eg. I2
- have low melting and boiling points + very poor conductors

Question 2

describe the structure of giant covalent substances

Answer 2

covalently bonded into a giant lattice structure, each atom has multiple covalent bonds = high melting point + rigid

Question 3

describe the structure of diamond

Answer 3

• macromolecular structure
• carbon atoms each bonded to 4 further carbon atoms
• hard + strong

Question 4

describe the structure of graphite

Answer 4

• macromolecular structure
• each carbon atom is bonded to 3 others in flat sheets
• electrons not used in bonding are released as free electrons which move between layers = can conduct electricity
• strong covalent bonds between carbon atoms within a layer + weak london forces between layers = slide over eachother = lubricant

Question 5

describe the structure of graphene

Answer 5

• single, 2D sheets of graphite that are just one atom thick
• sheets are formed of hexagonal carbon rings –> very strong, rigid material + lightweight
• delocalised electrons move = conduct electricity