Question

lesson name:
Is matter around us pure?
1.The metal which normally exist in liquid state is:

(a) sodium
(b) mercury
(c) magnesium
(d)iron
2.On the basis of composition of matter, milk is considered to be:

(a) pure substance
(b) impure substance
(c) compound
(d) element
3.State a reason why you think air is a mixture not a compound.
4.Write two points of difference between simple distillation and

fractional distillation. Write example where fractional distillation is

used.
5.(i) Name the techniques which you will apply for the separation of

mixtures:

(a) small pieces of metal in the engine oil of a car. (b) mud particles suspended in water. (c) oil from water

(d) sodium chloride from its solution in water

(e) camphor from salt. (f) wheat grains from husk

(ii) Classify the following as a chemical or physical change:

(a) Water boils to form steam

(b) Burning of paper

(c) An almirah gets rusted. (d) Making a fruit salad with raw fruits.
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Answer 1

Answer:

it is very long question so ask one by one

Answer 2

Answer:

The answer of your question is 1) Mercury

2) Impure substance