Unit 10 Chem- 10.3
Melting point
- The temp a solid changes into a liquid
- Stronger IMF's lead to higher melting points
- Vibrations between particles need to become strong enough to overcome attractions
Freezing point
- The temp a liquid changes into a solid
- Melting point=Freezing point
- liquid andsolid phases are in equalibrium
Amorphous Solids
Lack an ordered internal structure (atoms are randomly arranged)
- Rubber, plastic, wax, glass
Amorphous Solids- Glass
considered an intermediate between a solid and a liquid
Crystal Structures
Particles are arranged in a crystal Lattice
- Orderly, repeating, 3-D Pattern
Unit Cell
The smallest group of particles within a crystal that retains the geometric shape
- Determines overall shape
Allotropes
2 or more different molecular structures of the same element
- each has different physical properties due to it's
structure
- Only some elements have allotropes
- P, S, O, B, At