the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
The proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and mass slightly less than that of a neutron.
The electron is a subatomic particle. It is believed to be an elementary particle because it cannot be broken down into anything smaller. It is negatively charged, and may move almost at the speed of light.
The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.
In chemistry and physics, the atomic number of a chemical element (also known as its proton number) is the number of protons found in the nucleus of an atom of that element, and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z.
The mass number (A), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. Because protons and neutrons both are baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion.
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
the fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have.
Electron cloud is an informal term in physics. It is used to describe where electrons are when they go around the nucleus of an atom.
each of the actual or potential patterns of electron density that may be formed in an atom or molecule by one or more electrons, and that can be represented as a wave function.
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.
the lowest energy state of an atom or other particle.