period 3

• as you go across period 3, the atomic radium decreases as their is a higher nuclear charge. this is because there are a stronger electrostatic attraction between the nucleus and outer electrons
• sodium, magnesium and aluminium is a metallic bond
• silicon is a giant covalent bond/structure
• phosphate, sulphur and chlorine are simple molecules
• sodium, magnesium and aluminium has a high melting/boiling point as it has a metallic bond which needs a lot of energy to break
• silicon has a high melting/boiling point
• phosphate, sulphur and chloride have weak melting/boiling points as they have a weak van der walls force
• sodium reacts vigorously with water. equation = 2Na + 2H2O = 2NaOH + H2.
• what does sodium hydroxide produce when reacting with water ?

  it produces a blue precipitate and hydrogen gas is used to make a popping sound
• magnesium reacts very slowly with cold water. equation = Mg +2H2O = Mg(OH)2 +H2
• magnesium hydroxide produces a slightly blue precipitate and hydrogen gas can make the solution bubbly
• magnesium reacts with steam to form magnesium oxide 


  Mg + H2O = Mg(O) + H2
• sodium oxide produces a yellow flame and a white solid:


  4Na2 + O = 4Na2O
• magnesium oxide produces a white flame and white precipitate?

  2Mg + O = 2MgO
• aluminium oxide produces a white precipitate and white flame 


  Al3 + O2 = Al2O3
• silicon oxide produces a white precipitate and white flame?

  Si + O2 = SiO2
• phosphate oxide produces a white precipitate and white flame?

  P4 + 5O2 = P4O5
• sodium oxide and magnesium oxide is ionic as it has a very high melting point so there's a lot of energy required to break the strong electrostatic attraction
• aluminium oxide shows some covalent character as aluminium has a different electronegativity to oxide
• silicon oxide is a giant covalent as it has a high melting point
• when going across the period, the pH decreases with aluminium oxide and silicon oxide staying neutral as they are insoluble
• aluminium oxide acts as both a base and acid