Test 1

Question 1

Crystal

Answer 1

Regularly arranged atoms/molecules/ions in a pattern that repeats in multiple dimensions

Question 2

Lattice

Answer 2

an infinite array of points, the lattice points, each surrounded by an identical environment

Question 3

Basis

Answer 3

motif that is repeated at each lattice point

Question 4

Motif

Answer 4

atom/pair of ions/molecules

Question 5

unit cell

Answer 5

imaginary parallelepiped which can describe the whole of the crystal structure using the simplest possible descriptor

Question 6

square p-lattice

Answer 6

a=b
y=90

Question 7

rectangular p-lattice

Answer 7

a not = b
y=90

Question 8

rectangular c-lattice

Answer 8

a not = b
y=90

Question 9

hexagonal p-lattice

Answer 9

a=b
y=120

Question 10

oblique p-lattice

Answer 10

a not =b y not=90

Question 11

Primitive lattice

Answer 11

have only 1 lattice point inside the unit cell

Question 12

Centered lattice

Answer 12

have 2 lattice points inside the unit cell (one in the middle and then 1/4 on each side)

Question 13

cubic lattice

Answer 13

a=b=c, alpha=beta=gamma=90

Question 14

Tetragonal crystal system

Answer 14

a = b ≠ c
α = β = γ = 90°

Question 15

Orthorhombic crystal system

Answer 15

a ≠ b ≠ c; α = β = γ = 90°

Question 16

Monoclinic Crystal System

Answer 16

a≠b≠c
α=γ=90≠β

Question 17

Triclinic Crystal System

Answer 17

a≠b≠c
α≠β≠γ
one can be 90

Question 18

Rhombohedral

Answer 18

also known as trigonal

a=b=c
α=β=γ≠90

Question 19

Hexagonal crystal system

Answer 19

a=b≠c α=β=90 γ=120

Question 20

Miller planes

Answer 20

aka lattice planes, imaginary planes on which lattice points lie

Question 21

Simple or Primitive Cube

Answer 21

1 atom per unit cell

coordination number = 6

Question 22

Body centered cubic (BCC)

Answer 22

2 atoms per unit cell

coordination number = 8

Question 23

Face centered cubic (FCC)

Answer 23

4 atoms per unit cell

coordination number = 12

Question 24

hcp

Answer 24

hexagonal close packed ABABAB stacking

Question 25

octahedral hole

Answer 25

lines between two planar triangle spheres

Question 26

tetrahedral hole

Answer 26

formed by a planar triangle of touching spheres capped by a single sphere lying in the dip between them