How would you confirm that a colourless liquid given to you is pure water?

Which of the following materials fall into the category of 'pure substance'?

(a) Ice

(b) Milk

(c) Iron

(d) Hydrochloric acid

(e) Calcium oxide

(f) Mercury

(g) Brick

(e) Wood

(f) Air

Which of the following will show the 'Tyndall effect'?

(a) Salt solution

(b) Milk

(c) Copper sulphate solution

(d) Starch solution

Classify the following into elements, compounds and mixtures.

(a) Sodium

(b) Soil

(c) Sugar solution

(d) Silver

(e) Calcium carbonate

(f) Tin

(g) Silicon

(h) Coal

(i) Air

(j) Soap

(k) Methane

(l) Carbon dioxide

(m) Blood