The elements are classified into TWO(2) categories on the basis of their properties. The Two types are as follows,
3.1 PHYSICAL PROPERTIES
The easiest way to group the substances is by comparing physical properties.
Now take the look towards the below activities by collecting the samples of metals – iron, copper, aluminium, magnesium, sodium, lead, zinc.
The activity 3.1 says that to take the samples of iron, copper, aluminium and magnesium. Then we have to note the appearance of the samples.
Now we need to clean the surface of each sample by rubbing with sand paper. Now again note the appearance again.
Conclusion: Pure metals have shining surface and this property is called as Metallic Lustre.
In this activity 3.2 it takes small pieces of iron, copper, aluminium, and magnesium. Then cut them through a sharp knife. Note the observations.
[Precaution should be follow on the of sodium]
Try to cut sodium with a knife.
Conclusion: We found that metals are generally hard. This hardness varies from metals to metals.
The activity 3.3 tells to take pieces of iron, zinc, lead and copper. Then place one of the metal on a block of iron and strike it four(4) to five(5) times by hammer. This process will be repeated for the other metals. Record the shape of these metals.
Conclusion: We found that some metals beaten into thin sheets. This property is called Malleability. Better to remember that Gold and Silver are the most Malleable metals.
We have to collect the metals whose wire we have already seen in our day to day life. These are comes with aluminium, copper etc. in the wire form.
Conclusion: The ability of metals to be drawn into thin wires is called Ductility.
3.2 CHEMICAL PROPERTIES OF METALS
3.2.1 What happens when metals are burnt in air?
3.2.2 What happens when metals react with water?
3.2.3 What happens when metals react with acids?
Materials react with acids to give a salt and hydrogen gas.
=> Metal + Dilute acid —> Salt + Hydrogen gas
Sodium and potassium react vigorously even with cold water.
In this activity 3.11, it says to collect the metals samples. But mind that you need not to collect sodium and potassium at all. Cause sodium and potassium react vigorously with cold water.
If the collected samples are tarnished make it clean by rubbing with sand paper.
Now put the samples in dilute hydrochloric containing test tubes separately. Then you have to dip thermometers in the test tubes.
3.2.4 How do metals react with solutions of other metal salts?
3.2.5 The Reactivity Series
3.3 HOW DO METALS AND NON-METALS REACT?
[ REACTIONS OF METALS AND NON-METALS ]
3.3.1 Properties of ionic Compounds
3.4 OCCURANCE OF METALS
3.4.1 Extraction of Metals
3.4.2 Enrichment of Ores
3.4.3 Extracting Metals Low in The Activity Series
3.4.4 Extracting Metals in The Middle of The Activity Series
3.4.5 Extracting Metals Towards The Top of The Activity Series
3.4.6 Refining of Metals