An atom is the smallest unit of matter that gives the identity of a chemical element. Atoms are the building blocks of all matter and consist of three main subatomic particles: protons, neutrons, and electrons.
Various Parts of an Atom
Following are the key components of an atom:
- Nucleus:
- The central part of the atom.
- Contains protons and neutrons.
- It is very dense and contains nearly all of the atom’s mass.
- Proton (p+):
- Positively charged particle.
- Located in the nucleus.
- The number of protons defines the element (e.g., hydrogen has 1 proton, helium has 2).
- Neutron (n0):
- Neutral particle (no charge).
- Also located in the nucleus.
- Neutrons contribute to the atom’s mass and stability.
- Electron (e-):
- Negatively charged particle.
- Found in electron orbits (or electron clouds) around the nucleus.
- Electrons are much smaller than protons or neutrons and move very quickly.
- Electron Orbit (Electron Cloud):
- The region around the nucleus where electrons are likely to be found.
- Electrons occupy different energy levels or shells (e.g., K, L, M shells).
- The arrangement of electrons in these orbits determines the chemical properties of the atom.