2.33. Fundamental Particles http://www.ck12.org
TABLE2.7:(continued)
Year Discovery
1911 Ernest Rutherford discovers the proton, the first particle
to be discovered in the nucleus of the atom.1932 James Chadwick discovers the neutron, another particle
in the nucleus.1964 Murray Gell-Mann proposes the existence of quarks,
the fundamental particles that make up protons and
neutrons.1964-present Through the research of many scientists, many other
fundamental particles (except gravitons) are shown to
exist.For almost 100 years after Dalton discovered atoms, they were accepted as the fundamental particles of matter. But
starting in the late 1890s with the discovery of electrons, particles smaller and simpler than atoms were identified.
Within a few decades, protons and neutrons were also discovered. Ultimately, hundreds of subatomic particles were
found. You can learn how such tiny particles are discovered by watching the video at this URL: http://www.ehow.
com/video_5112658particle-accelerator.html.