How compounds are broken apart?

Hint Compounds can break down into simple molecules by heating or applying energy in any other form. Antoine Lavoisier is known as "The father of modern chemistry" who first explained about breakdown of compounds into simpler substances.

Complete step by step answer:
The compounds are pure substances which are made up of one or more than one type of atom and it can easily be broken down into the individual elements by chemistry. This breakdown of compounds into individual elements cannot be done physically.
The compounds that can be broken apart in chemical reactions into smaller molecules are called decomposition reactions.
For example:
-\[{{H}_{2}}O\to {{H}_{2}}+{{O}_{2}}\]
Water molecules can be break down into diatomic molecules that are hydrogen and oxygen gas in a chemical reaction known as electrolysis.
- \[2NaCl\to 2Na+C{{l}_{2}}\]
Sodium chloride is broken down into elemental sodium chloride gas by electrolysis.
Decomposition reaction is feasible under suitable conditions such as temperature, pressure, medium that is acidic or basic etc. These factors differ from each set of compounds taken. Most of these kinds of reactions require some energy as input. The energy may be in form of heat, light
In above two mentioned decomposition reactions the breakdown of compounds takes place when electricity is produced. During the process of electrolysis some amount of electricity is produced in order to break the compound.

Note: Decomposition reaction actually should be endothermic as it is using energy which was given to it as an input. But not always it is endothermic, this also can be exothermic in some cases. Separation of elemental metals from ores are extracted out by applying the decomposition reaction concept.