Section 9.4- Crystals

Question 1

when the particles are fixed in definite positions about which they vibrate

Answer 1

solids

Question 2

two types of solids

Answer 2

amorphous solids
crystalline solids

Question 3

a few solids have non ordered arrangement or pattern for the particles that compose them and are known as

are arranged randomly

no fixed melting point

Answer 3

amorphous solids

Question 4

examples of amorphous solids

Answer 4

tar, butter, grease, glass, and some plastics

Question 5

characterized by particles arranged in regular and repeated tree-dimensional pattern

definite melting point or very narrow range of temperature over which it melts

Answer 5

crystalline solid

Question 6

the simplest repeating unit in a crystal is called the

Answer 6

unit cell

Question 7

unit cell arrangement in which has atoms on only the corners of the cube

Answer 7

simple cubic

Question 8

two unit-cell arrangements that are derived from the simple cubic unit cell

Answer 8

body-centered cubic arrangement (bcc)
face-centered cubic arrangement (fcc)

Question 9

unit cell arrangement that has one atom in the center, making it possible for 3 atoms diagonally through the cube

Answer 9

body-centered cubic arrangement

Question 10

unit cell arrangement that has multiple atoms in the center, making five atoms on each side of the cube

Answer 10

face-centered cubic arrangement

Question 11

packs the most atoms into the smallest amount of space

Answer 11

face-centered cubic arrangement

Question 12

the fcc is also known as the

Answer 12

cubic close packing

Question 13

T/F: all crystals have cubic arrangements

Answer 13

FALSE

Question 14

one of the most efficient crystal structures is

allows atoms to be packed together as tightly as possible and minimizes empty space

Answer 14

hexagonal close packing (hcp)

Question 15

metals that have hcp

Answer 15

titanium, magnesium

Question 16

in the body-centered cubic structure, each atom has ____________ identical neighbors

Answer 16

EIGHT

Question 17

both the hexagonal close packed structures and the face-centered cubic arrangements allow _______________ identical neighbors for each atom.

Answer 17

TWELVE