T1W7L1: bonding & structure

network §

giant lattice

• covalent network
• metallic network
• ionic network (lattice)

bonding and structure §

• giant metallic lattice structure (Na, Mg, Al)

• physical properties of metal §

  • electrical conductivity: all metals can conduct electricity
  • solid at room temperature (except mercury)
  • most of metals are grey solids.
    • describe metal using grey solids on observation (except gold - yellow, and salmon pink for copper)
    • do not describe metals with silver. silver is an element, not a colour description.
• giant molecular structure (C and Si)
  • carbon is bonded in a huge molecular network.
    • carbon can have allotropes: - diamond: all bonds are covalent and strong, so diamond has the highest melting point on the periodic table, as well as the hardest mineral.
      • graphite
      • buckminsterfullerene (bucky balls)
• simple covalent molecules (P4, S8, Cl2)

metallic bonding §

• electron becomes delocalised.
• each sodium atom has electrons delocalised.
• definition of metallic: electrostatic forces of attraction between cations of metal and sea of delocalised electrons.
• physical properties:
  • high melting point.
  • high boiling point.
  • good electrical conductivity (can be explained by a number of the presence of delocalise electrons)
  • malleable (you can reduce the metals in to sheets)
  • ductile (able to be drawn out in a long thin wire without breaking it.)
• melting point. sodium does not have high melting point, however magnesium and aluminium is high.
• aluminium has higher electrostatic forces of electron, because 3 electrons could be delocalised in aluminium compared to magnesium, which means stronger metallic bonds exist.
• • more delocalised electrons (3e power atom)
• • higher change on cation (+3)
• • stronger metallic bond.
• the metal does not break and is extremely malleable because it is cations in a sea of delocalised electrons, and it instead slides.
• when force is applied, the object does not shatter, and the existence of cations and electrons slide against the other.

comparing ionic compounds to ??? §

• ions of the same charge next to each other repels
• fell asleep

electrical conductivity §

• for period 3

  • sodium is a good conductor.
  • magnesium has more delocalised electrons, and is a slightly better conductor.
  • aluminium is a great conductor, as it has the most delocalised electrons.
  • silicon to argon cannot conduct electricity.
    • silicon is a medium to hold conductors in semi conductors.

• did the worksheet on the onenote :)