(12) solid state inorganic II

Question 1

name the four different types of metallic structures

Answer 1

cubic
body centred cubic
hexagonal close packed
cubic close packed

Question 2

describe a cubic structure

Answer 2

cube spheres that are in contact along the edges of the cube
NOT CLOSE PACKED
52% of space occupied
touches 6 adjacent spheres

Question 3

describe a body centred structure (bcc)

Answer 3

cube of spheres
NOT CLOSE PACKED 
additional sphere at the centre
sphere in middle touches all 8 corner spheres 
corner spheres not in contact 
68% of space is occupied

Question 4

describe the difference in the two close packed structures

Answer 4

the 3rd layer of atoms is different

Question 5

alloy

Answer 5

structure made up of different elements which has metallic properties

Question 6

define subsitutional alloys

Answer 6

some of the host metal atoms are replaced by the other metal atoms of similar size
they have similar electronegativies and crystal structure

Question 7

define inter metallic compounds

Answer 7

have a fixed position which form definite structures with different arrangements to the parent compound

Question 8

describe bonding in metals

Answer 8

atoms that have lost electrons to form cations. There is a regular array of cations in a sea of valence electrons

Question 9

TBC - fermi levels and band theory

Answer 9

yes