I1

Question 1

metallic structure ASSUMES that…

Answer 1

atoms are hard spheres

Question 2

materials with lattice structures are…

Answer 2

crystalline with highly ordered atoms and ions

Question 3

in terms of space efficiency which is better hexagonal or square array?

Answer 3

hexagonal

Question 4

close packed layer contains what shaped gaps?

Answer 4

triangular

Question 5

most efficient way of packing close packed structures?

Answer 5

second layer spheres over first layer gaps

Question 6

what are the 2 types of gap in close packed layer?

Answer 6

triangle up and down

Question 7

cubic close packed structure (ccp) pattern…

Answer 7

ABCABC

Question 8

hexagonal close packed (hcp) pattern…

Answer 8

ABAB

Question 9

ccp and hcp coordination number

Answer 9

12

Question 10

coordination number

Answer 10

number of closest neighbouring spheres

Question 11

ccp coordination number explained

Answer 11

6 in plane, 3 below and 3 above

Question 12

interstitial sites/holes

Answer 12

cavities between layers from stacking

Question 13

interstitial hole shapes

Answer 13

tetrahedral/octahedral

Question 14

simple/primitive lattice pattern

Answer 14

AA

Question 15

simple/primitive lattice coordination number

Answer 15

6

Question 16

body-centred lattice pattern

Answer 16

ABAB, B layer over holes

Question 17

unit cell

Answer 17

basic structural unit when translated in 3 dimensions gives extended lattice