Bulk Properties (WJEC GCSE Chemistry: Combined Science)

• Diamond, graphite, fullerenes, carbon nanotubes and graphene are all made from carbon atoms but have different bulk properties 
• Bulk properties include:
  • Melting and boiling point
  • Electrical and thermal conductivity
  • Flexibility
  • Hardness 
• The individual atoms do not have these properties
• The bulk properties arise due to the type and strength of bond that the compounds contain and how the atoms are arranged 
• For example, within diamond, each carbon atom is bonded to four other carbon atoms by strong covalent bonds
  • This makes diamond extremely hard
• In graphite, each carbon atom is bonded to three other carbon atoms and forms layers
  • These layers have weak intermolecular forces between them allowing the layers to slide 
  • This makes graphite soft and slippery 
• The individual atoms in diamond and graphite do not have these properties; they are due to the structure and bonding within each substance 

Diagram to show the bonding within diamond and graphite 

Graphite forms layers making it soft and slippery whereas diamond is hard 

Summary table of bulk properties of different forms of carbon

Diamond	Graphite	Fullerenes	Carbon nanotubes	Graphene
Cannot conduct electricity  Extremely hard  High melting / boiling point	Can conduct electricity  Soft and slippery  High melting / boiling point	Can conduct electricity Slippery	Can conduct electricity High tensile strength Good thermal conductor	Extremely strong  Can conduct electricity and heat  Almost transparent

 

• Atoms not having the same properties as the bulk material can also be observed in the case of silver 
• Bulk silver is a shiny and malleable metal that doesn't corrode 
  • Its main use is in jewellery 
• Silver nanoparticles are between 1-100 nm in diameter with a large surface area to volume ratio 
• In this form, silver has antibacterial, antifungal and antiviral properties:
  • They are used in deodorant to kill bacteria that cause odours
  • They coat the inside of fridges to kill the bacteria that cause odours
  • They are used in some socks to kill bacteria and keep socks fresh  

Bulk silver's main use is in jewellery, whereas silver nanoparticles have antibacterial properties