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Science, Evolution, and Creationism, by the National Academies, focuses on teaching evolution in today's classrooms. Check out the other publications in our online store.


This simplistic model of an atom shows protons as red spheres in the central nucleus. This model is NOT to scale; to match the scale of the nucleus the electrons (yellow) should be much smaller and much further away from the nucleus.
Original artwork by Windows to the Universe staff (Randy Russell).

A proton is a type of tiny particle. All atoms have protons in them, along with electrons. Most atoms also have neutrons.

Protons and neutrons are just about the same size. However, protons are much, much bigger than electrons. A proton is more than 1,000 times as heavy as an electron!

Protons and electrons have an electrical charge. Protons have a charge of +1, while electrons have a charge of -1.

Protons and neutrons are found in the nucleus of an atom. Usually there are about as many protons as neutrons. For example, the nucleus of a normal oxygen atom has 8 protons and 8 neutrons.

Sometimes protons are found outside of atoms. Some of those protons can get moving very, very fast. Protons like that 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 September 17, 2010 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