Question

Fill in the blanks:
Grinding of wheat grain changes its size. It is a ________________ change.

Answer 1

Hint:The changes that take place in the universe can be broadly divided into two categories: Physical and Chemical changes. Physical changes only involve changes which can be reversed or do not involve chemical equations.

Complete answer:
When wheat grains are broken down into simpler fragments by grinding then its grain size only changes so this is a physical change and the chemical composition of wheat remains constant. On the other hand when this wheat is baked into bread and then there is a permanent change in the chemical composition or the structure of the molecule. Hence that would have been a chemical change.

So, the correct answer would be: Grinding of wheat grain changed its size. It is a “Physical” change.

Note:
The physical changes are those that can only change the appearance of the substance but the components of the substance remain the same, while the chemical change changes the components of the substance into a completely different substance. Certain examples in this regard will be helpful. The melting of ice to liquid water and the boiling or vaporization of the liquid water to gaseous water vapour are examples of physical changes as the chemical formula of water does not alter in the entire process. On the other hand, examples of chemical change include the rusting of iron in the presence of water vapour and oxygen to form iron oxides is a transformation in the chemical composition of iron completely. Hence, this is a chemical change.