Lesson name:Is matter around us pure?1.The metal which normally exist in liquid state is:(a) sodium (b) mercury (c) magnesium (d)iron2.On the basis of composition of matter, milk is considered to be:(a) pure substance (b) impure substance (c) compound (d) element3.State a reason why you think air is a mixture not a compound.4.Write two points of difference between simple distillation andfractional distillation. Write example where fractional distillation isused.5.(i) Name the techniques which you will apply for the separation ofmixtures:(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.​