Question

identity physical and chemical changes, and uunderstand the difference between atoms, elements and compounds.

Answer 1

A physical change is a reversible change in which only the physical properties of a substance changes, such as colour, shape, size. Eg. Crumpling of a paper

A chemical change is an irreversible change in which the chemical composition of the substance changes. Eg. Electrolysis of water

DIFFERENCES

1) Atom- An atom is the smallest constituent unit of matter.

2) Element- An element is an atom having the same no. Of protons. Eg. Oxygen

3) Compound - it is a heterogenous combination of 2 or more elements