Period 3

• How well does sodium conduct electricity?

  It is the worst conductor among metals
• What is the reaction of sodium with acid?

  Na + acid → H2 + salt
• What are the observations when sodium reacts with cold water?

  Floats, fizzes, and melts
• What is the appearance of sodium?

  Metallic and shiny
• What is the equation for sodium's reaction with cold water?

  2Na + 2H2O → 2NaOH + H2
• What happens when sodium reacts with oxygen?

  It produces a bright yellow flame
• What is the equation for sodium's reaction with oxygen?

  2Na + ½ O2 → Na2O
• What is the appearance of magnesium?

  Metallic and shiny
• How well does magnesium conduct electricity?

  Between sodium and aluminum
• What are the observations when magnesium reacts with cold water?

  Very slow reaction with pH 10
• What is the equation for magnesium's reaction with cold water?

  Mg + 2H2O → H2 + Mg(OH)2
• What happens when magnesium reacts with steam?

  It reacts much faster
• What is the equation for magnesium's reaction with steam?

  Mg + H2O → MgO + H2
• What are the observations when magnesium reacts with oxygen?

  Bright white flame forms white powder
• What is the equation for magnesium's reaction with oxygen?

  2Mg + O2 → 2MgO
• What is the appearance of aluminium?

  Metallic and shiny
• How well does aluminium conduct electricity?

  It is the best conductor in period 3
• What is the reaction of aluminium with cold water?

  There is no reaction
• What are the observations when aluminium reacts with oxygen?

  Bright flame forms white powder
• What is the equation for aluminium's reaction with oxygen?

  4Al + 3O2 → 2Al2O3
• Why is aluminium considered unreactive?

  It is covered by unreactive Al2O3
• What happens if Al2O3 is scratched off?

  Aluminium reacts rapidly with air
• What is the appearance of silicon?

  Semimetal and semiconductor
• What is the reaction of silicon with oxygen?

  It produces white powder
• What is the equation for silicon's reaction with oxygen?

  Si + O2 → SiO2
• What is the appearance of phosphorus?

  Non-metal with low melting and boiling points
• What is the reaction of phosphorus in excess oxygen?

  White phosphorus ignites spontaneously
• What is the equation for phosphorus's reaction in excess oxygen?

  4P + 5O2 → P4O10
• What is the reaction of phosphorus in limited oxygen?

  It forms phosphorus trioxide
• What is the equation for phosphorus's reaction in limited oxygen?

  4P + 3O2 → P4O6
• What is the appearance of sulfur?

  Non-metal with low melting and boiling points
• What is the reaction of sulfur with oxygen?

  It forms colorless sulfur dioxide gas
• What is the equation for sulfur's reaction with oxygen?

  S + O2 → SO2
• What are the different types of structure and bonding displayed by the period 3 oxides?

  • Na: ionic lattice
  • Mg: ionic lattice
  • Al: ionic lattice with covalent character
  • Si: giant covalent
  • P: simple molecular covalent
  • S: simple molecular covalent
• What is the trend in melting points for period 3 oxides?

  • Highest: MgO
  • Lowest: SO2
  • Increases for metals due to stronger ionic bonding
  • Al2O3 is lower due to covalent character
  • Decreases with size for simple molecular molecules
• Which period 3 oxides are basic?

  Na2O and MgO
• What is the reaction of Na oxide with water?

  Na2O + H2O → 2Na+ + 2OH-
• What is the pH of the reaction of Na oxide with water?

  pH = 14
• What is the reaction of Mg oxide with water?

  MgO + H2O → Mg2+ + 2OH-
• What is the pH of the reaction of Mg oxide with water?

  pH = 9-10