Alpha Particles: These are positively charged particles consisting of two protons and two neutrons. They were used in the Gold Foil Experiment to probe the structure of atoms.
Gold Foil Experiment: This experiment conducted by Ernest Rutherford involved firing alpha particles at a thin gold foil to investigate the structure of atoms.
Electron Cloud Model: This model describes electrons as existing in regions called orbitals or electron clouds around the nucleus of an atom.