The role of Electrons


Electron shells

Electrons do not just spin anywhere around the nucleus. They are found in Shells or energy levels. Electrons (e-) have a negative charge and are very light. They spin around the nucleus at very high speeds. Electrons are placed into shells or energy levels around the nucleus, the first and innermost shell can only hold 2 electrons, on the middle ring it fits 8 electrons and on the outer most shell also fits 8 electrons. Atoms are electrically neutral, they have no charge, therefore the number of protons in an atom equal the number of the elements in an atom. The shells of the atom are called K, L, M and N.

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An ion is an atom or molecule which the total number of electrons is not equal to the total number of protons. This gives the atom a positive or negative electrical charge. Ions can be created both chemically and physically. If a neutral atoms loses around one or more electrons, it has a positive charge and if it has gains electrons, it has a negative charge.