atomirakenteessa
Atomirakenteessa refers to the structure of an atom. At the center of an atom is the nucleus, which contains protons and neutrons. Protons are positively charged, while neutrons have no charge. Electrons, which are negatively charged, orbit the nucleus in specific energy levels or shells. The number of protons in an atom's nucleus determines its atomic number and defines the element. Atoms are electrically neutral when the number of electrons equals the number of protons. Isotopes of an element have the same number of protons but different numbers of neutrons. The arrangement of electrons, particularly in the outermost shell, dictates an atom's chemical behavior and its ability to form bonds with other atoms. Understanding atomirakenteessa is fundamental to chemistry and physics, explaining phenomena from the properties of materials to the nature of light. The concept has evolved significantly over time, with models progressing from Dalton's indivisible spheres to the more complex quantum mechanical model that describes electron probability clouds rather than fixed orbits.