allotropes

• What are allotropes?

  Different forms of the same element
• Why do allotropes have the same chemical properties?

  They are composed of the same element
• What causes allotropes to have different physical properties?

  Different bonding of atoms
• What are the allotropes of sulphur?

  • Monoclinic Sulphur
  • Rhombic Sulphur
• What are the allotropes of phosphorous?

  • Red Phosphorous
  • White Phosphorous
  • Black Phosphorous

  
• What are the allotropes of carbon?

  • Diamond
  • Graphite
• What are the allotropes of oxygen?

  • Molecular Oxygen (O₂)
  • Ozone (O₃)
• What type of bonds are present in carbon atoms?

  Strong covalent bonds
• What is the structure of Giant Molecular Structures?

  They have a 3D network of covalent bonds
• What are the two allotropes of carbon mentioned?

  Diamond and graphite
• How is each carbon atom in diamond arranged?

  In a tetrahedral arrangement bonded to 4 others
• What are the physical properties of diamond?

  • Very high melting point (almost 4000°C)
  • Very hard and difficult to scratch
  • Does not conduct electricity
  • Insoluble in water and organic solvents
  • Transparent
• Why does diamond have a very high melting point?

  A lot of energy is needed to break covalent bonds
• Why is diamond very hard?

  Strong covalent bonding makes it difficult to scratch
• Why does diamond not conduct electricity?

  Absence of mobile electrons in bonding
• Why is diamond insoluble in water and organic solvents?

  Covalent bonds are too strong for solvents
• What makes diamond ideal for cutting tools?

  Its hardness
• How is diamond used as a glass cutter?

  Because it is one of the hardest substances
• What are the uses of diamond based on its physical properties?

  • Edges of cutting tools (drilling bits)
  • Glass cutters due to hardness
• What type of bonds are present in graphite?

  Strong covalent bonds

  
• What forces exist between the layers of graphite?

  Weak van der Waals' forces

  
• Describe the structure of graphite.

  • Each carbon atom bonds to three others
  • Forms six-membered hexagonal rings
  • Arranged in parallel layers
  • Weak van der Waals' forces between layers

  
• How are the carbon atoms arranged in graphite?

  In flat layers forming hexagonal rings
• What happens to the layers of graphite when a force is applied?

  They can easily slide away from each other
• What is the melting point of graphite?

  3652 °C
• Why does graphite have a high melting point?

  Strong covalent bonds require much heat energy
• How does graphite conduct electricity?

  It has free (mobile) electrons
• What are the physical properties of graphite?

  Soft, smooth, and slippery
• Why is graphite considered smooth and slippery?

  Weak van der Waals' forces allow sliding
• Why is graphite insoluble in water and organic solvents?

  Strong covalent bonds prevent solvent interaction
• What are the uses of graphite based on its properties?

  • Pencil points: soft, smooth, slippery
  • Electrodes: good electrical conductor
  • Lubricant: allows layers to slide easily
• Why is graphite used to make pencil points?

  It is soft, smooth, and slippery
• How does graphite function as an electrode?

  It has delocalised free electrons
• Why is graphite used as a lubricant?

  Weak forces allow layers to slide