crystals from notes

Question 1

what is a crystallin soilds

Answer 1

have organized arrangments of particles and sitinct shapes

have 5 classification
1. ionic crystals
2. metallic crystals
3. molecular crystals
4. covalent network crystals

Question 2

what are ionic crystals

Answer 2

• forms from interaction of metal and non-metal
• the ions arrange in crystal lattice structure with alternative packing of positive and negative ions

Question 3

what are metallic crystals

Answer 3

• in soild state, metals
• a structure of closely packed atoms held together by electrostatic interactions and free moving electrons

Question 4

what are molecular crystals

Answer 4

soild composed of individual molecules held together by IM ex. water or soild sulfur

Question 5

what are covalent network crystals

Answer 5

soild in which the atoms form covalent bonds in interwoven network ex. diamond and graphite

Question 6

what are the properties of ionic crystals

Answer 6

• hard
• brittle
• high melting point
• dissolve in polar solvents to form electrolytes (conductive)

Question 7

what are the properties of metallic crystals

Answer 7

• 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

Question 8

how to differentiate ionic and metallic crystals through testing

Answer 8

• heat test (molecular melts faster)
• soluble test (ionic will dissolve)

Question 9

list the crystal structures in order of easiest to hardest to melt (highest melting/boiling point)

Answer 9

1. molecular
2. metallic
3. ionic
4. covalent network