Class 10 Science — Chapter 1
Chemical Reactions and Equations (Short Revision Notes)
1. What is a Chemical Reaction?
A process in which one or more substances react to form new
substances with entirely different properties.
* Real-life Examples:
* Making of curd from milk.
* Rusting of iron.
* Digestion of food in our body.
2. Reactants and Products
* Reactants: The substances that take part in a chemical reaction
(Written on the Left Side).
* Products: The new substances formed after the reaction (Written on
the Right Side).
* Example: 2H₂ + O₂ → 2H₂O (Here, H₂ and O₂ are Reactants, and H₂O is
the Product).
3. Balancing Chemical Equations
* Rule: Law of Conservation of Mass - Mass can neither be created nor
destroyed in a chemical reaction. Therefore, the number of atoms on
both sides must be equal.
Chemical Reactions and Equations (Short Revision Notes)
1. What is a Chemical Reaction?
A process in which one or more substances react to form new
substances with entirely different properties.
* Real-life Examples:
* Making of curd from milk.
* Rusting of iron.
* Digestion of food in our body.
2. Reactants and Products
* Reactants: The substances that take part in a chemical reaction
(Written on the Left Side).
* Products: The new substances formed after the reaction (Written on
the Right Side).
* Example: 2H₂ + O₂ → 2H₂O (Here, H₂ and O₂ are Reactants, and H₂O is
the Product).
3. Balancing Chemical Equations
* Rule: Law of Conservation of Mass - Mass can neither be created nor
destroyed in a chemical reaction. Therefore, the number of atoms on
both sides must be equal.
