Microscopic Structures

• Basic, stable 3d structure
• High melting and boiling points
• Formed by natural solidification
• Regular pattern
• Cubic lattice

e.g. Sodium Chloride, NaCl

• Lots of small crystals
• Regular structure interrupted by grain boundaries
• Vacancies- gaps in structure
• Edge dislocation occurse

e.g. Silicon, Si, Copper, Cu, Brass

• No regular order of atoms
• Disorganised arrangement

e.g. glass, cement

• Long chain polymers
• Can be coiled or rotated to straighten out

e.g. polythene, polystyrene, rubber