The Atom and Nuclear Fusion

The Atom and Nuclear Fusion

1. Rutherford's scattering showed that atoms have a positive nucleus

   • Ernest Rutherford, Hans Geiger and Ernest Marsden fired alpha particles (positively charged) at thin gold foil. Most of the alpha particles just went straight through but the odd one cam straight back at them. Rutherford then deducted that this meant that Most of the mass of a gold atom was concentrated at the centre in a tiny nucleus. The rest of the atom must be mainly empty space as most of the alpha particles went straight through. The nucleus also had to be positively charged otherwise the alpha particles would not have been repelled .

2. The Nucleus is held together by the strong force

   • The Nucleus contains positiviely charged proton particles which repel each other. The nucleus doesnt fly apart because its held together by an attractive force much greater than the repulsive electrostatic force between the protons this is called the strong force. The strong force only has a very short range. At larger seperations the srtong force is so weak that it disappears

3. Nuclei have to be brought close together to fuse

   • Two nuclei can fuse to create a larger nucleus, releasing energy when they do. For example hydrogen nuclei fuse to make helium nuclei. Nuclei can only fuse if they overcome the repulsive electrostatic force and get close enough for strong force to take over. For that you need lots of energy which means high temperature

4. Nuclear Fusion Converts Mass into Energy

   • Energy = mass x [speed]^2