crystals from notes Flashcards
1
Q
what is a crystallin soilds
A
have organized arrangments of particles and sitinct shapes
have 5 classification
1. ionic crystals
2. metallic crystals
3. molecular crystals
4. covalent network crystals
2
Q
what are ionic crystals
A
- forms from interaction of metal and non-metal
- the ions arrange in crystal lattice structure with alternative packing of positive and negative ions
3
Q
what are metallic crystals
A
- in soild state, metals
- a structure of closely packed atoms held together by electrostatic interactions and free moving electrons
4
Q
what are molecular crystals
A
soild composed of individual molecules held together by IM ex. water or soild sulfur
5
Q
what are covalent network crystals
A
soild in which the atoms form covalent bonds in interwoven network ex. diamond and graphite
6
Q
what are the properties of ionic crystals
A
- hard
- brittle
- high melting point
- dissolve in polar solvents to form electrolytes (conductive)
7
Q
what are the properties of metallic crystals
A
- low IE
- strong forces of attraction between + nuclei and e-, making closely packed
- do not have similar properties
- “electron sea theory”
-malleability - electrical conductivity
-hardness
8
Q
how to differentiate ionic and metallic crystals through testing
A
- heat test (molecular melts faster)
- soluble test (ionic will dissolve)
9
Q
list the crystal structures in order of easiest to hardest to melt (highest melting/boiling point)
A
- molecular
- metallic
- ionic
- covalent network
