GCSE Physics - Atomic Structure

• The first atomic model was created by J.J. Thomson in 1897
• JJ Thomson's model was named the Plum Pudding Model
• The Plum Pudding model said atoms were balls of positive charge with electrons embed within it
• JJ Thompson discovered electrons
• Rutherford held an experiment and discovered there must be a tiny concentration in the centre of an atom, a nucleus, and that most of the atom is empty space
• Rutherford's experiment was held in 1909
• Rutherford's experiment involved firing at gold foil with alpha particles.
• Rutherford's experiment lead to the current model of the atom.
• Niels Bohr discovered energy levels and electron shells in the atom.
• Rutherford is credited with the discover of the proton.
• James Chadwick discovered the neutron in 1932,
• James Chadwick's discovery explained the imbalance between the atomic and mass numbers
• The radius of a nucleus is around 1 x 10^-10 m
• Electrons gain energy from absorbing EM radiation, and move to a higher energy level further from the nucleus
• Electrons can lose energy by releasing EM radiation and moving to a lower energy level.