chemistry: period 3

• melting point from Na to Al increases

  • metallic bond strength increases
  • number of electrons that each atom can contribute to the sea of delocalised electrons increases
• Si has the highest melting point

  giant covalent structure

  stong covalent bonds between silicon to silicon atom which require lots of energy to break
• Sulfur has a higher melting point than phosphorus because it has more polarizable electrons so more id id forces
• phosphorus chlorine and argon have low melting points because they are all simple covalent molecules
• electrical conductivity of metals is high

  metals have a sea of delocalised mobile electrons to carry the charge

  Al has a higher electrical conductivity than Na bcs Al can contribute upto 3 electrons per atom instead of one like Na
• Silicon is a metalloid, can conduct electricity when dipped in impurity such as arsenic

  remaining are all simple covalent structures with no free moving electron
• greater the number of electrons, greater the amount of charge that can be carried
• P, S, Cl, and Ar do not conduct electricity bcs they are simple molecular structures and tehy have no free moving electrons
• phosphorus and sulfur show several oxidation states as they can expand their octets
• basic oxides (Na2O and MgO) + acids to form salt + water