Materials: Metals and Non- Metals

Chemical properties of metals:

1. Reaction with oxygen:-
   Metals react with oxygen to form metallic oxides. These are basic oxides because they react with water to form bases. E.g. Magnesium burns in air to form magnesium oxide.Magnesium reacts with water to form magnesium hydroxide.
   2 Mg + O2 ---> 2 MgO MgO+ H2O ---> Mg(OH)2
2. Reaction with water:-
   Metals react with water to form metal hydroxides and hydrogen.
   Eg. Sodium reacts with water to form sodium hydroxide and hydrogen.
   2 Na + 2 H2O ----> 2 Na OH + H2
   Magnesium reacts with water to form magnesium hydroxide and hydrogen.
   Mg + H2O ----> Mg(OH)2+ H2
3. Reaction with acids:-
   Metals react with acids to form metallic salts and hydrogen.
   Eg. Zinc reacts with dilute hydrochloric acid to form zinc chloride and hydrogen.
   Zn + 2 HCl ----> ZnCl2+ H2
4. Metals replace metals:-
   A more reactive metal replaces a less reactive metal from its salt solution.
   Eg. Magnesium replaces copper from copper sulphate solution to form magnesium sulphate and copper.
   Mg + CuSO4 ----> MgSO4+ Cu
   Zinc replaces copper from copper sulphate solution to for zinc sulphate and copper.
   Zn + CuSO4 ----> ZnSO4 + Cu

Chemical properties of non-metals:

1. Reaction with oxygen:
   Non-metals react with oxygen to form non-metallic oxides. These oxides are acidic oxides because they react with water to form acids.
   Eg. Sulphur burns in air to form sulphurdioxide. Sulphurdioxide reacts with water to form sulphurous acid.
   S + O2 ---> SO2
   SO2+ H2O ---> H2SO3
2. Reaction with water:
   Non-metals do not react with water
3. Reaction with acids:
   Most non-metals do not react with acids.
   Some non-metals like sulphur react with concentrated nitric acid to form sulphur dioxide, nitrogen dioxide and water.
   S + 4 HNO3 ---> SO2+ 4 NO2+2 H2O

Physical properties of metals:

• Metals are solid except mercury.
• Metals are hard.
• Metals are malleable that is can be beaten into thin sheets.
• Metals are ductile that is can be drawn into wires.
• Metals produce ringing sounds are called sonorous.
• Metals are lustrous.
• Metals are good conductors of heat and electricity.

Physical properties of non-metals:

• Non- metals are solid, liquid or gas.
• Non- metals which is solid are brittle (diamond is the hardest).
• Non- metals are soft and dull in appearance.
• Non- metals are not malleable, and break down into powdery mass on tapping with a hammer.
• They are not sonorous.
• They are poor conductors of heat and electricity..

Copper cannot displace zinc from its salt solution: because Zinc is more reactive than copper. A more reactive metal can replace a less reactive metal, but a less reactive one cannot replace a more reactive metal. Therefor Copper cannot displace zinc from its salt solution. Sodium and potassium are stored in kerosene because Sodium metal is very reactive. It reacts vigorously with oxygen and water. A lot of heat is generated in the reaction. It is, therefore, stored in kerosene.

1. Sulphur burning in air: Sulphurburns in air to form sulphurdioxide. Sulphurdioxide reacts with water to form sulphurous acid.
   S + O2 ---> SO2
   SO2+ H2O ---> H2SO3
   
2. Sulphur reacts with concentrated acid to form sulphur dioxide, nitrogen dioxide and water.
   S + 4 HNO3 ---> SO2+ 4 NO2+2 H2O
3. when Iron nail is placed in copper sulphate solution iron replaces copper from copper sulphate, thus nails becomes copper plated and blue colour of copper sulphate solution disappears and solutions turns from blue to light yellowish. Following reaction occurs:
   Copper sulphate (CuSO4) + Iron nail (Fe) ---> iron sulphate (FeSO4) + Copper (Cu)

when dilute sulphuric acid is poured in a copper plate then copper undergo reaction with acid to form metal salts CuSO4 a blue crystalline solid and hydrogen gas:

Cu (Copper) + H2SO4 (Sulphuric Acid) => CuSO4(Copper sulphate) + H2 (Hydrogen gas)