Question

How was the nucleus was discovered?

Answer 1

Discovery of Nucleus

• The nucleus was discovered by Sir Ernest Rutherford in 1911.
  Rutherford Gold Foil Experiment
• He performed a gold foil experiment which leads to the discovery of the nucleus.

• In Rutherford’s gold foil experiment, a beam of alpha particles was shot at a thin sheet of gold foil.
• Most of the alpha particles passed straight through the gold foil.
• But a small number of alpha particles were deflected slightly.
• And an even smaller fraction of alpha particles were deflected more than 90 degrees from their path.
• This led Rutherford to propose the nuclear model of an atom.
• According to Rutherford, an atom consists of a very small, positively charged nucleus surrounded by negatively charged electrons.

• In the gold foil experiment, he showed that the atom is composed of mostly empty space with a tiny, dense, positively-charged nucleus.
• Based on the number of alpha particles deflected in the experiment.
• Rutherford calculated that the nucleus took up a tiny fraction of the volume of the atom.