Atomic structure

• The model for atomic structure has evolved over time.
• Plum Pudding Model: Initially, atoms were thought to consist of a sphere of positive charge with evenly distributed negative charges within it.
• Electron Shell Model: It is now known that atoms consist of a small, dense central nucleus surrounded by orbiting electrons in electron shells.
• The nucleus contains protons and neutrons, giving it an overall positive charge and almost the entire mass of the atom.
• In a neutral atom, the number of electrons is equal to the number of protons.