Question

What is an atom, element, molecule, and compound? What is an example of each?

Answer 1

Hint : The concept of an atom or the element constitutes the basic or the foundation of chemistry. The concept is like a stepping stone to study all the chemical reactions and processes in the chemical world. While the small sized atom constitutes the microscopic world which cannot be seen through naked eyes and only through electron microscope. Elements and compounds make up the macroscopic world that one can see through naked eyes.

Complete Step By Step Answer:
Atom- An atom is the smallest particle of matter. The property of an element depends on its constituting atoms. Atoms can be subdivided into smaller subatomic particles like protons, neutrons and electrons. An atom also consists of a small size nucleus. Dalton was the first chemist to formulate a description about atoms.
Example-Neon atom $(Ne)$ and Hydrogen atom $(H)$
Molecule-A group of 2 or more atoms when combined together by chemical bond constitutes a molecule. They retain chemical and physical properties of the substance. A molecule can be homonuclear (consisting of same atoms) or heteronuclear (consisting of different atoms).
Example- $HCl$ is a molecule made up of hydrogen $(H)$ and chlorine $(Cl)$ atoms. It is an example of a heteronuclear diatomic molecule.
Element-It is a pure substance which cannot be subdivided further into parts by ordinary chemical processes. There are a total 118 elements in the periodic table. They are made up of the same type of atoms.
Example-Silver $(Ag)$ and gold $(Au)$
Compound-Compounds are chemical substances made up of 2 or more elements combined in a fixed ratio. Compounds can be subdivided into small parts chemically.
Example-Baking soda $(NaHC{O_3})$ , Octane $({C_8}{H_8})$ etc.

Note :
It is important to understand that all these components are actually somewhere important to understand the Matter classification. Matter is anything that occupies space and has mass. It can be further subdivided into pure substances and Mixture. Elements and compounds make the pure substances while mixtures contain elements combined not in a fixed ratio. A mixture can be separated by physical means. For example, a mixture of sugar and water.