question_answer 20)

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  

Answer:

Elements : The elements are regarded as the building blocks of the universe. So (a) sodium, (d) silver, (f) tin and (g) silicon are elements. Compounds : It is a pure substance made up of two or more elements chemically combined in a fixed proportion by mass. So, (e) calcium carbonate, (k) methane and (l) carbon dioxide are compounds. Mixtures : It is a substance containing two or more substance (elements or compound) in any proportion. So (b) soil, (c) sugar solution, (h) coal, (i) air, (j) soap and (m) blood are mixtures.