Materials : Metals And Non-metals

Sulphur is considered as a non metal as it possesses physical properties to that of non metals like no lustre, soft and brittle, non malleable, non ductile etc.

Metals are malleable, which means they can be hammered (beaten) into thin sheets (or flattened). Zinc being a metal can be hammered on beating.

Piece of coal is considered as a non metal which can be broken into smaller pieces when hammered.

Ductility is considered as a physical property of Metals and Sulphur being a non-metal, so it is not ductile. When stretched, Sulphur break into pieces and do not form wires.

Metals are generally hard. This means that most of the metals cannot be cut easily but sodium being an exception is soft and can be easily cut with a knife or any sharp object.

Mercury is considered as a metal which is in liquid state at room temperature.

Metals like Copper, Silver and Gold are considered as less reactive metals which do not react with dilute hydrochloric acid to produce hydrogen gas.

The Intensity/Vigour of reaction of a metal with water depends upon its chemical reactivity. Sodium being a very reactive metal reacts violently even with cold water.

Aluminium reacts with hydrochloric acid and also with sodium hydroxide solution to produce hydrogen gas.

Phosphorus is considered as a non metal which reacts and catches fire on exposure to air.

Sulphur which is a non metal forms an acidic oxide, i.e. Sulphur Dioxide (SO₂) which turns blue litmus red.

Colour of the copper metal is not responsible for it to be used for electrical conduction wire as colour has nothing to do with the electrical conductivity of the metal.

Metals which can be easily cut with a knife are

-Sodium

-Potassium

These both are considered as soft metals.

Oxygen which is a non metal is used by all the living organisms for breathing. Thus Oxygen is important for maintaining our life.

The two major non metals which are present in fertilizers and enhance the growth of plants are :-

-Nitrogen

-Phosphorus

The non metal which is used to disinfect water in water purification plants is Chlorine as it has the ability to kill germs.

Iodine is a non metal which is used to make purple coloured solution called tincture of iodine which is used to apply on wounds and cuts as an antiseptic.

No, There will be no colour change on adding copper turnings in zinc sulphate solution as copper being a less reactive metal than zinc cannot displace zinc from it salt solution. So, displacement reaction doesnot take place.

Bells are made of metals as metals have sonorous property. The ringing sound produced by metals is known as sonorous.So, this is the reason why bells are made up of metals.

Mercury metal is used for making thermometers as mercury is in liquid state at room temperature.

Zinc>Iron>Copper (Order of reactivity)

As we can se that zinc is the most reactive metal and copper is the least reactive metal amongst the three given metals and reactivity of iron is in between to that of Zinc and copper. So, Zinc metal can displace the other two metals from their salt solutions.

When a copper statue is exposed to moist air for along period of time it acquires a dull green coating. This dull green coating is due to formation of Copper Hydroxide[Cu(OH)₂] and Copper carbonate[CuCO₃] formed when copper reacts with moist air.

This Green coating is commonly known as ‘Basic Copper Carbonate’ and the process of formation of green coating on copper objects is known as corrosion of copper.

(a) Iron is a metal.

(b) Metals are good Conductors of electricity.

If we replace iron nails with the wooden stick the bulb will not glow as wood is a non-conductor of electricity.

In Beaker A we will observe a reddish brown colour of copper on the iron nail and blue coloured solution of copper sulphate will become yellowish green due to the formation of iron sulphate. This is because iron is more reactive than copper and it displaces copper from its salt solution of copper sulphate. In beaker B, no change is observed because copper being less reactive does not displace iron which is more reactive than copper from its ferrous sulphate solution.

Iron is a metal but the tablet is not made up of iron metal whereas the tablet is made up of a salt of iron. So, the appearance of the tablet is not similar to that of iron.

(a)-(iii)

(b)-(iv)

(c)-(i)

(d)-(v)

(e)-(ii)

(a): No Change.

(b): Metals are good conductors of heat and electricity.

(c): No Change, The reason behind this is that metals are sonorous.

(d): Oxides of non-metals are acidic in nature and oxides of metals are basic in nature.

(e): A more reactive metal displaces a less reactive metal from its salt solution in water.

To explain that iron is more reactive than copper, Take about 50ml of water in a beaker to which add 5gm of Copper sulphate in order to obtain copper sulphate solution which is blue in colour. Put a clean iron nail in this solution and keep the beaker for sometime undisturbed.

We will observe that the blue colour of copper sulphate solution starts fading gradually and the iron nail gets covered with a red-brown layer of copper metal. It is because iron is more reactive than copper, so it displaces copper metal from its solution of copper sulphate.

So, it is the copper metal that is free from its compound which forms a red-brown layer on the surface of iron nail. This shows that iron is more reactive than copper.

The name of the product formed in the reaction of sulphur and Oxygen is sulphur dioxide gas. When sulphur dioxide is dissolved in Water, Sulphurous acid is formed. The suphurous acid turns blue litmus paper to red. Generally oxides of non metals are acidic in nature.

After completing the paragraph write two questions which you can raise on the basis of this information.

Q1- What is the nature of oxides of non-metals?

Q2- Which gas is formed when Sulphur reacts with oxygen?

Across

1: Iron

2: Ductile

3: Sonorous

Down

4: Gold

5: Mercury

6: Aluminium

7: Fertilizer

8: Malleable