Structures

Question 1

describe ionic lattices

Answer 1

Ions in a lattice are arranged in a regular repeating pattern so that positive charges cancel out negative charges. Electrically neutral

Question 2

describe metallic lattices

Answer 2

Metals form giant metallic lattices in which the metal ions are surrounded by a ‘sea’ of delocalised electrons
- good conductors due to delocalised electrons

Question 3

simple covalent structures

Answer 3

simple molecules

Question 4

giant covalent structures

Answer 4

have very high melting and boiling points because the compounds have a large number of covalent bonds linking the whole structure

Question 5

are giant covalent structures hard or soft

Answer 5

they tend to be hard such as diamond or silicon oxide as difficult to break 3d network but some soft like graphite as forces weak between carbons layers

Question 6

are giant covalent structures soluble

Answer 6

Insoluble

Question 7

can giant covalent structures conduct

Answer 7

do not conduct but graphite has delocalised electrons between the carbon layers which can carry a charge
Diamond and silicon(IV) oxide do not conduct electricity as all four outer electrons on every carbon atom are involved in a covalent bond so there are no freely moving electrons available

Question 8

describe graphite

Answer 8

carbon bonded to three others forming layer of hexagons leaving one free electron which can carry a charge and conduct electricity.
layers are held weakly by intermolecular forces so layers can slide making graphite soft and slippery

Question 9

describe diamond

Answer 9

each carbon atom bonds with four other carbons, forming a tetrahedron

Question 10

Describe graphene

Answer 10

Graphene consists of a single layer of graphite which is a sheet of carbon atoms covalently bonded forming a continuous hexagonal layer. it is only one atom thick