(a) What is meant by (i) elements (ii) compound, and (iii) mixtures?
Write down the names of two elements, two compounds and two mixtures.
(b) Classify the flowing into elements, compounds and mixtures:
Marble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk
(a) (i) Element: A substance that cannot split into two or more simpler substance by chemical methods.
Examples: carbon and oxygen are non-metals, aluminium, copper are metals
(ii) Compound: It is a substance consisting of two or more elements combined chemically in a fixed proportion by mass.
Example: Water and sodium chloride
(iii) Mixture: Mixture is a substance that is made up of two or more paticles or substances mixed by physical process.
Examples are Milk and wood
(b) Elements – Gold, Diamond, Graphite
Compounds – Common salt, Sea water, Marble
Mixtures – Brass, Sand, Petroleum, Chalk, Air