Best Summary of structure of atom

An atom consists of a dense, central nucleus containing positively charged protons and neutral neutrons, surrounded by a cloud of negatively charged electrons orbiting in shells. The nucleus holds almost all atomic mass, while electrons occupy most of the volume, creating a mostly empty space. Key Components of Atomic Structure: Nucleus: The small, dense, positively charged center composed of protons and neutrons (nucleons). Protons ( ): Positively charged subatomic particles. The number of protons defines the atomic number ( ) and determines the element type. Neutrons ( ): Electrically neutral subatomic particles. They contribute to atomic mass but not charge. Electron Cloud: The region surrounding the nucleus where electrons exist. Electrons ( ): Negatively charged subatomic particles with very little mass. Shells/Energy Levels: Electrons occupy specific, defined shells or energy levels around the nucleus. Neutrality: A neutral atom contains an equal number of protons and electrons. Key Concepts and Definitions: Atomic Number ( ): Total number of protons in the nucleus. Mass Number ( ): Total sum of protons and neutrons ( ). Isotopes: Atoms of the same element (same ) with different numbers of neutrons. Ions: Atoms that have gained or lost electrons, resulting in a positive or negative charge. Atomic Models: Developed over time, including models from Dalton (indivisible), Thomson (plum pudding), Rutherford (nuclear model), and Bohr (orbital mode)