Metals and non-metals

Metals
Metals have following properties –

1.  Lustrous or shining
2. Good conductor of electricity
3. Good conducted of temperature
4. Ductile – can be drawn into wire
5. Malleability – can be drawn into sheet
6. Sound – produce sound.
7. Mostly solid. Mercury is a liquid metal.

E.g. – Gold, silver, iron, copper.

Non metals
Non metals have following properties –

1. Non lustrous
2. Not good conductor of electricity
3. Not good conductor of temperature
4. Not ductile
5. Not malleable
6. No sound
7. Three states of matter – solid, liquid, gas

E.g. – paper, water, oxygen.

Semi metals

Carbon, boron, Silicon, germanium, Arsenic, antimony, tellurium and Polonium are called semi metals.

Metal reactivity

Some metals are very active. They cannot exist in free state in nature. Example K, Na, Ca, Mg, Al.

Some metals have medium capacity to react. Example Zn, Fe, Pb.

Some metals exist freely in nature. Example Cu, Ag,  Au.

Reactivity series of metals

Take 5 beakers

1. CuSO₄ + Zn
2. CuSO₄ + Fe
3. ZnSO₄ + Cu
4. FeSO₄ + Cu
5. ZnSO₄ + Fe

Result – In beaker 1 & 2 colour change.

Principal- More reactive elements displaces less reactive elements

Metallic mixture

Steel – Iron and carbon

German silver – Copper, Nickel, Zinc

Gunmetal – Copper, tin, lead

Oxidation and reduction

Metals reacts with oxygen present in nature

4Fe+3O₂ -> 2Fe₂O₃

2Ag+O₂ -> AgO

Iron rusts because it is oxidizes in presence of free oxygen. Silver also oxidizes in the same way.

The property of iron and silver is called corrosion to prevent iron from corrosion or rusting we use paint.

Ores

Ores are minerals having large quantity of metals. Some common metal and ores are –

S. No.	Metal	Ore
1	Aluminum	Bauxite
2	Iron	Hematite
3	Lead	Galena
4	Mercury	Cinnabar
5	Zinc	Calamine
6	Calcium	Dolomite