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Physical Environment > Atom |
This site tells the story of the history of the universe. Click Earlier and Later to follow the story. Note: Many facts have been simplified to make them easier to understand. |
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About 300 thousand years after the Big Bang, the Universe had cooled enough for electrons to be captured by protons and alpha particles to form atoms.
An electron is pulled towards a proton because their opposite electric charges attract each other. They stick together to form a totally new kind of object called an atom of hydrogen. In the same way two electrons were attracted to each alpha particle, which contained two protons, and were held close to it. The atom they made is called a helium atom. Atoms are fantastic things. Around the outside of the atom the electron forms a large thin shell. Inside the atom is empty space, except for the tiny heavy proton at the center. An atom is like a football. The electron in an atoms is like the skin of the football. Under this skin the atom is almost empty. At the center is something a football doesn't have. Held at the center by the electric force is the tiny proton. This is called the nucleus of the atom. The young Universe was full of hot atoms, moving around and bouncing off each other. They made a gas. Once all the electrons were atoms trapped in atoms, the fog of the Universe cleared. To get an idea of the size of atoms why not visit Soccearth? For pictures of atoms see this page. |
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Physical Environment > Atom |
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Basic Information |
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