X CBSE Science Notes

Can you provide me Key notes and summary of the chapter with examples on Chemical Reactions and Equations for CBSE (Central Board of Secondary Education) Class 10th Science?

[Kiran Chandar]

Key notes and summary of the chapter with examples on Chemical Reactions and Equations for CBSE (Central Board of Secondary Education) Class 10th Science is as follows:

Chemical Reaction : – Whenever a chemical change occurs we can say that a chemical reaction has taken place eg – Food gets digested in our body
– Rusting of iron.


Chemical Equation :– A chemical reaction can be expressed symbolically by using chemical equation eg magnesium is burnt into air to form magnesium oxide can be represented as


Mg + O2 → MgO


– We can observe or recognise a chemical reaction by observing change in state, colour, by evolution of gas or by change in temperature.


Physical state of the reactant and products are mentioned to make chemical reaction more informative. eg we use (g) for gas, (l) for liquid, (s) for solid and (aq) for aqueous.


Balancing Equation :– We balance the chemical equation so that no. of atoms of each element involved in the reaction remain same at the reactant and product side.