Atomic structure - Atoms are composed of a nucleus surrounded by one or more energy levels. The nucleus contains protons and neutrons, and the energy levels contain electrons, moving in orbitals at the speed of light.
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| Atomic Structure |
What are atoms composed of? If you were a chemist or an atomic physicist, your reply would be "hundreds of subatomic particles, from hadrons to quarks," and you would stress that atoms are extremely complex. However, for our purposes we need to consider only three subatomic units neutrons, protons, and electrons.
We can describe the atom as consisting of two regions. First, there is a center core, or nucleus, in which we find the protons (positively charged particles) and neutrons (particles with no charge). The second is a region surrounding the nucleus where electrons (negatively charged particles) travel around the nucleus in paths called energy levels. Electrons travel at extremely high speed. In a sense, electrons form a cloud as they whiz around the nucleus. Each energy level is made up of
one or more orbitals specific regions, at some distance from the nucleus, in which an electron is found at least 90 percent of the time. The shape of an orbital will vary, depending on how many electrons are whizzing around the nucleus. The atoms of different elements have different numbers of protons, neutrons, and electrons.
The nucleus of an atom is very dense, compared with the energy levels around it. Try to envision it in the following way. If you had an atom with a diameter as long as two football fields, the nucleus in the center would have a diameter only as thick as five dimes stacked together. All around the nucleus, electrons would be mere specks whizzing around to form a cloud. In reality, most of the structure of an atom is empty space.
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