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.

Why new products are formed in a chemical reaction?

What is a chemical change?

How can we prevent rusting?

Explain the process of rusting.

Explain physical reaction along with examples.

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

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.