Metals and non - metals

PART-A

Q1: name any ten metals.

Ans:iron, copper, aluminium, sodium copper, silver, magnesium, gold, Mercury ,calcium.

Q2: metals have high tensile strength, explain. Also give one example of how this property of metals is used.

Ans: metals are very strong. It cannot be broken easily. Steel cables are used to carry heavy loads.

Q3: why can't you

(A) draw wires from a piece of wood or coal .

Ans: because wood or coal are brittle and not flexible.

(B) use nylon or jute ropes for  electrical transmission?

Ans: no, because these are bad conductor of electricity.

(C) use a cooking utensils made of cardboard.

Ans:because , cardboard is a bad conductor of heat. It will not give heat in all direction.

Q4: name five metals which are gaseous at ordinary temperature? 

Ans: hydrogen coma oxygen nitrogen , neon,  chlorine.

Q5:name two metals which react vigorously with cold water. Name one metal which, if ignited, continuous to burn in stream?

Ans: sodium and potassium can react with cold water. Magnesium can burn in stream.

Q6: mention three uses of oxygen.

Ans: 1. We use oxygen to breathe.

2. It help in combustion.

3. Liquid oxygen is used to burn rocket fuel.

Q7: mention three uses of nitrogen.

Ans: 1. Plants use nitrogen to make proteins.

2. It is used to store blood.

3. It is filled in food packets.

Q8: define an alloy.

Ans: it is a mixture of metals and nonmetals. 

For example ,Steel.

PART-B

Q1: mention five physical characteristics of metals.

Ans: 1. Metals are hard.

2. Metals are lustre.

3. Metals are good conductor of heat.

4. Metals are good conductor of electricity.

5.  Metals are sonorous.

Q2: mention five properties of nonmetals.

Ans: 1. Non metals are soft.

2. Non metals are lustreless.

3 Non metals are bad conductors of heat.

4. Non metals are bad conductor of electricity.

5.  Non metals are non sonorous.

Q3: name a non metal which when Red Hot reacts with the stream, what happens as a result of the reaction ?

Ans: carbon is a non metal it reacts with the stream to form carbon monoxide and hydrogen gas. The mixture of CO and H2 is called water gas.

C + H2O is =C O + H2 / water gas.

Q4: mention three uses of matter, giving reasons.

Ans:1. aluminium metal is used to form wires, because it is good conductor of electricity.

2. Aluminium is used to farm fires because it is malleable.

3. iron , copper are used to form utensils. Because they are good conductor of heat.

Q5: describe the uses of carbon.

Ans: 1. Graphite is used in pencil.

2. Diamond is used to cut glass.

3. Diamond is used in necklace.

PART - C 

Q1: how would you use the activity series while studying the displacement of hydrogen from acids by metals?

Ans: metals which are above hydrogen in activity series can displace hydrogen from an acid , but metals which are below hydrogen that cannot displace hydrogen from an acid.

For example ,

2 NA + 2HCL = 2NaCl +H2 

Cu +HCL =no reaction.

CHAPTER- METALS AND NON- METALS 

BY ANMOL

8TH(D) {1}