Protons and neutrons present in the atomic nucleus and electrons present in the extra-nuclear region make up an atom.
Atoms are the building blocks of matter. The word 'atom' was originally meant to indicate the smallest indivisible unit of matter. However, research revealed that an atom was in fact not indivisible and that it consisted of certain subatomic particles. What are the parts of an atom? An atom is made up of protons, neutrons, and electrons.
The central portion of an atom is known as the atomic nucleus. It consists of protons which carry positive charge and neutrons which carry no electric charge. The negatively charged electrons orbit the atomic nucleus.
The protons and neutrons in an atomic nucleus contribute to the atom's mass (atomic mass). The electrons floating in the region around the nucleus are extremely lightweight subatomic particles.
Protons are positively charged and electrons are negatively charged. Then how does an atom not have electric charge? Do the neutrons neutralize the electric charge of an atom?
If atoms bore electric charge, we would get electrical shocks on touching anything around us. As atoms make up matter and matter makes up the universe, we would probably have to live in an electrically charged world (literally).
But thanks to the equal number of protons and electrons in an atom, matter does not possess electric charge. Atoms have an equal number of protons and electrons. This nullifies the electric charge, thus making them electrically neutral.
Atoms get together to form molecules. When atoms of different elements come together, compound molecules are formed. There are two types of compounds, ionic and covalent.
- The ions of ionic compounds are bound together due to electrostatic forces between oppositely charged bodies.
- When atoms share pairs of electrons to form chemical bonds, the compounds thus formed are known as covalent.
Chemical reactions between atoms of different elements result in the formation of various compounds. Being the fundamental units of matter, it won't be an exaggeration to say that atoms are omnipresent; they are within you, around you, and everywhere.