Atoms are the building blocks of matter and are responsible for everything we observe in the visible universe. The two main components of an atom are the nucleus and the cloud of electrons. The nucleus contains positively charged and neutral subatomic particles, whereas the cloud of electrons contains tiny negatively charged particles.

The nucleus is found at the center of the atom and contains subatomic particles that are called protons and neutrons. Protons carry a positive charge, whereas neutrons carry no charge. The protons and neutrons are held together in the nucleus by the nuclear strong force, which overcomes the repulsion between positively charged protons.

An atomic nucleus is surrounded by a cloud of electrons. Electrons carry a negative charge that is equal and opposite to the charge carried by a proton. To form a neutral atom, the number of electrons has to equal the number of protons in the nucleus.