Question

What happens in a chemical reaction?

Answer 1

In order to answer this problem we should first understand about the chemical change. A physical transition, such as changing states or dissolving, does not result in the formation of a new substance; however, a chemical change does.

Complete answer:
Physical effects such as heat and light emissions, precipitation formation, gas evolution, or colour change are usually observed when a chemical reaction occurs. An exothermic reaction is one in which heat energy is released by a chemical reaction. An endothermic reaction is one in which the chemical reaction consumes energy.
Chemists classify the many different reactions into broad categories. Chemical reactions are a part of our everyday lives. A chemical reaction occurs when you boil an egg. After the egg has been fried, it cannot be changed back to its original state.
When we use formulas instead of terms, we can make chemical equations more simple and useful. In a chemical reaction, reactants react with each other to produce products, which are different compounds. Only the atoms present in the reactants will end up in the products of a chemical reaction. There are no new atoms formed, and there are no atoms destroyed.
The chemical equation depicts the reaction of methane ($C{H_4}$, a major component of natural gas) with molecular oxygen (${O_2}$) to produce carbon dioxide ($C{O_2}$) and water.
$C{H_4}\left( g \right){\text{ }} + {\text{ }}2{O_2}\left( g \right){\text{ }} \to {\text{ }}C{O_2}\left( g \right){\text{ }} + {\text{ }}2{H_2}O\left( l \right)$

Note:
Reactants come into contact with each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to form the products in a chemical reaction.