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The Universe at Your Fingertips 2.0 DVD from the Astronomical Society of the Pacific is in our online store, filled with Earth and space science resources.


This movie shows one way of thinking about an atom. In this atom, the electrons are yellow. They zip around the outer edges of the atom. In the middle of the atom is the nucleus. It has protons (red) and neutrons (blue). Each proton and electron has an electrical charge. A proton has a positive (+) charge. An electron has a negative () charge. This movie isn't quite the right scale for real atom. The electrons should be much smaller than the protons and neutrons. The electrons should also be much, much further away from the nucleus. If the nucleus was this size, the electrons would zing around in a space larger than a major sports stadium! An atom is mostly empty space.
Original artwork by Windows to the Universe staff (Randy Russell).

An electron is a type of very, very tiny particle. Electrons, protons, and (usually) neutrons are the parts of an atom.

Electrons have a small electrical charge. Electrons have a negative (-) charge, while protons have a positive (+) charge. Neutrons don't have a charge.

Electrons are much smaller than protons and neutrons. Protons and neutrons are more than 1,800 time larger than electrons!

Protons and neutrons are in the nucleus of an atom, at its center. Electrons zing around the nucleus, sort of like high speed planets orbiting a star.

Sometimes electrons get knocked loose from their atom. They zip around through space at very high speeds. Sometimes they get speeded up even more by magnetic fields. Fast-moving electrons are a type of particle radiation.

Atomic Physics and Particle Physics

Fundamental Physics relevant to Space Weather

Space Weather

A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF

Last modified July 30, 2008 by Randy Russell.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA