Physical and Chemical Changes

Explain the changes occurring in burning of candle.

Write the chemical formula of blue vitriol.

Explain why burning of wood and cutting it into small pieces are considered as two different types of changes.

Apart from new products, many other things accompany a chemical change, what are those things?

Explain chemical reaction along with examples.

What is a chemical change?

Explain physical reaction along with examples.

Why new products are formed in a chemical reaction?

How can we prevent rusting?

Setting of curd is regarded as a chemical change, explain why?

Explain the process of rusting.

Which one is better technique to obtain sugar from sugar solution- crystallization or evaporation to dryness?

State the condition necessary for the occurrence of any reactant.