C3 structure and bonding

• The electronegativity difference between two atoms determines the polarity of a covalent bond.
• A polar molecule has an uneven distribution of charge, with one end being more positive (delta plus) and the other end being more negative (delta minus).
• Polar bonds can form dipoles that attract to create hydrogen bonds.
• Nanoparticles could enter the atmosphere and there are health risks
• Simple compound cannot conduct electricity because they don’t have an overall charge
• An alloy is a mixture of two or more metals that have different melting points.
• Metals have regular layers on top of each other with outer electrons moving freely
• Properties of metals are :

  ductile

  conductors

  malleable

  sonorous
• Covalent compounds share their valence electrons
• Properties of graphene :

  reactive

  strong

  conductors

  low density
• The properties of diamond make it useful as cutting tools, abrasives and jewellery
• Nanotubes can be used as sensitive sensors
• Nanotubes are :

  strong

  have high density

  conductors

  cylindrical
• Graphene is made up of hexagonal rings of carbon atoms joined by covalent bonds.
• Graphite has layers of hexagons stacked on top of one another with weak van der waal forces between them.
• Fullerenes are hollow shaped carbon molecules
• Graphite has delocalised electrons. they can slide over each other freely. there is a spare atom from each layer which moves freely and conducts electricity
• Polymers are small molecules bonding to each other forming a chain
• Intermolecular forces are forces of attraction between molecules of the same type.
• A giant covalent structure is many atoms held by a network of bonds
• Properties of giant covalent structure:

  conductors

  insoluable

  High melting point
• Metals have high melting points because their interatomic forces are strong
• Ionic compounds have high melting points as ionic bonds are very strong
• Giant covalent structures have high melting points due to the strength of the covalent bonds holding them together
• Increasing temperature increases the kinetic energy of particles which causes more collisions with other particles so there will be more free electrons available to carry charge
• Giant covalent structures have low melting points as intermolecular forces are weak
• Covalent structures have low melting points as intermolecular forces are weak
• The conductivity of metals decreases when they dissolve in water or acid as the H+ ions displace some of the metal ions from the lattice