Question

in our day to day life 4 chemical reactions and explain

Answer 1

1 Burning gas in a stove 
2 Mixing chemicals 
3 Acid Rain
4 Oxidizing food for energy  
A physical change, such as a state change or dissolving, does not create a new substance, but a chemical change does.
In a chemical reaction, the atoms and molecules that interact with each other are called reactants.
In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.

hope its help u..

Answer 2

acid rain
brushing our teeth with tooth paste  (calcium)
rusting of iron
pasteurization of milk.