Ch 10 Section 3 Flashcards Preview

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Flashcards in Ch 10 Section 3 Deck (66):
1

the particles of a solid are more closely packed than those of a

liquid or gas

2

intermolecular forces between particles are therefore much more

effective in solids

3

all interparticle attractions exert stronger effects in solids than in the corresponding

liquids or gases

4

attractive forces tend to hold the particles of a solid in

relatively fixed points, with only vibrational movement around fixed points

5

because the motions of the particles are restricted in this way, solids are more ordered than

liquids and are much more ordered than gases

6

there are two types of solids:

crystalline solids and amorphous solids

7

Most solids are crystalline solids→they

consist of crystals

8

a crystal is a substance in which the particles are arranged in an

orderly, geometric, repeating pattern

9

noncrystalline solids, including glass and particles, are called

amorphous solids

10

an amorphous solid is one in which the particles are arranged

randomly

11

unlike liquids and gases, solids can maintain a definite

shape without a container

12

crystalline solids are

geometrically regular

13

even the fragments of a shattered crystalline solid have distinct

geometric shapes that reflect their internal structure

14

amorphous solids maintain a definite shape, but they do not have the

distinct geometric shapes of crystalline solids

15

the volume of a solid changes only slightly with a change in

temperature or pressure

16

solids have definite volume because their particles are

packed closely together

17

there is very little empty space into which the particles can be

compressed

18

crystalline solids generally do not flow because their particles are held in

relatively fixed positions

19

melting is the physical change of a solid to a liquid by the addition of

energy as heat

20

the temperature at which a solid becomes a liquid is its

melting point

21

at this temperature, the kinetic energies of the particles within the solid overcome the a

attractive forces holding them together

22

the particles can then break out of their positions in

crystalline solids, which have definite melting points

23

amorphous solids have no definite

melting point

24

amorphous solids have the ability to flow over a

range of temperatures

25

amorphous solids are sometimes classified as supercooled liquids, which are substances that retain certain liquid properties even at

temperatures at which they appear to be solid

26

these properties exist because the particles in amorphous solids are arranged

randomly, much like the particles in a liquid

27

unlike the particles in a true liquid, however, the particles in amorphous solids are not

constantly changing their positions

28

substances are most dense in the

solid state

29

solids tend to be slightly denser than

liquids and much denser than gases

30

the higher density results from the fact that the particles of a solid are more

closely packed than those of a liquid or a gas

31

solid hydrogen is the least dense solid; it has a density of about

1/320 the densest element, osmium

32

solids are generally less compressible than

liquids

33

some solids, such as wood and cork, may seem compressible, but they are

not

34

diffusion does occur in

solids

35

the rate of diffusion in solids is millions of times slower than in

liquids

36

crystalline solids exist either as single crystals or as

groups of crystals fused together

37

the total 3d arrangement of particles of a crystal is called a

crystal structure

38

the arrangement of particles in the crystal can be represented by a coordinate system called a

lattice

39

the smallest portion of a crystal lattice that shows the three-dimensional pattern of the entire lattice is called a

unit cell

40

each crystal lattice contains many

unit cells packed together

41

a crystal and its unit cells can have any one of

seven types of symmetry which enables scientists to classify crystals by their shape

42

crystal structures can also be described in terms of the types of particles in them and the types of

chemical bonding between the particles

43

(types of crystals) ionic crystals: ionic crystal structure consists of positive and

negative ions arranged in a regular pattern

44

(types of crystals) ionic crystals: the ions can be monatomic or

polyatomic

45

(types of crystals) ionic crystals: ionic crystals form when group 1 or group 2 metals combine with group 16 or group 17

nonmetals or nonmetallic polyatomic ions

46

(types of crystals) ionic crystals: the strong binding forces between the positive and negative ions in the crystal structure give the ionic crystals

certain properties→hardness, brittleness, high melting pts., good insulators

47

(types of crystals) covalent network crystals: each atom is covalently bonded to its

nearest neighboring atoms

48

(types of crystals) covalent network crystals: the covalent bonding extends throughout a network that includes a

very large number of atoms

49

(types of crystals) covalent network crystals: three-dimensional covalent network solids include

diamond, quartz, silicon carbide, and many oxides of transition metals

50

(types of crystals) covalent network crystals: the subscript x in these formulas (e.g. (SiO2)x ) indicates that the component within the parentheses

extends indefinitely

51

(types of crystals) covalent network crystals: the network solids are nearly always very

hard and brittle

52

(types of crystals) covalent network crystals: they have rather high melting points and are usually

nonconductors or semiconductors

53

(types of crystals) metallic crystals: the metallic crystal structure consists of

metal cations surrounded by a sea of delocalized valence electrons

54

(types of crystals) metallic crystals: the electrons come from the metal atoms and belong to the

crystal as a whole

55

(types of crystals) metallic crystals: the freedom of these delocalized electrons to move throughout the crystal explains the

high electric conductivity of metals

56

(types of crystals) covalent molecular crystals: the crystal structure of a covalent molecular substance consists of covalently bonded

molecules held together by intermolecular forces

57

(types of crystals) covalent molecular crystals: if the molecules are nonpolar then there are only weak

London dispersion forces between molecules (e.g. hydrogen, methane, benzene C6H6)

58

(types of crystals) covalent molecular crystals: in a polar covalent molecular crystal molecules are

held together by dispersion forces, somewhat stronger dipole-dipole forces, and sometimes by even stronger hydrogen bonding (e.g. H20, ammonia NH3)

59

(types of crystals) covalent molecular crystals: the forces that hold polar/nonpolar molecules together in the structure are much weaker than the

covalent chemical bonds between the atoms within each molecule

60

(types of crystals) covalent molecular crystals: covalent molecular crystals thus have

low melting points

61

(types of crystals) covalent molecular crystals: easily..., are relatively..., and are good...

vaporized; soft; insulators

62

amorphous comes from greek word for

without shape

63

the atoms that make up amorphous solids are not arranged in

a regular pattern

64

glasses are made by cooling certain molten materials in a way that

prevents them from crystallizing

65

plastics (amorphous solid) are easily molded at high

temperatures and pressures and are used in many structural materials

66

amorphous semiconductors are used in

electronic devices