Atoms are made of three fundamental particles. Neutrons are neutral particles with no electric charge. Protons are positively charged particles that determine what element an atom is. Together, neutrons and protons form the nucleus at the center of the atom. Electrons orbit around this nucleus, completing the atomic structure.
The proton is a fundamental particle with a positive electric charge. It has a mass of approximately 1.67 times 10 to the minus 27 kilograms and is located in the atomic nucleus. The number of protons in an atom determines its atomic number and defines what element it is. For example, hydrogen has one proton, carbon has six protons, and oxygen has eight protons.
Neutrons are neutral particles with no electric charge, but they have nearly the same mass as protons. While protons repel each other due to their positive charges, neutrons act as nuclear glue, helping to hold the nucleus together. Different numbers of neutrons in the same element create isotopes, which are atoms with the same number of protons but different masses.
The atomic nucleus forms when protons and neutrons cluster together at the center of an atom. Despite protons repelling each other due to their positive charges, the strong nuclear force holds them together. This force is much stronger than electromagnetic repulsion but only works at very short distances. Different elements have different numbers of protons in their nuclei, like hydrogen with one proton or carbon with six protons and six neutrons.
A complete atom consists of a tiny, dense nucleus at the center containing protons and neutrons, surrounded by much larger electron shells where electrons orbit. The nucleus is incredibly small compared to the overall atom size, but contains almost all the atom's mass. Electrons have negative charge and balance the positive charge of protons, making the atom electrically neutral. This three-particle system creates all the matter we see around us.