An Ion is a molecule that actively gains or looses one or more valance electrons. There's cations and anion. Cations are positively charged electrons, and are formed when it has more protons than electrons. Anions are negatively charged ions and are formed when it has more electrons than neutrons. Cations are the metal elements in ionic form, and anions are nonmetal elements in ionic form. A cation and an anion combined forms an ionic compound ionically bonded together. Ex: |dw:1441334705206:dw|
An ion is an atom or group of atoms in which the number of electron s is different from the number of proton s. If the number of electrons is less than the number of protons, the particle is a positive ion, also called a cation. If the number of electrons is greater than the number of protons, the particle is a negative ion, also called an anion. When an atom of an element is short an electron, a plus sign is placed after its chemical symbol as a superscript to indicate that fact. For example, a carbon atom with 5 electrons (the nucleus has 6 protons) is symbolized C + . If the element is short 2 or more electrons, a numeral is also placed in the superscript, directly before the plus sign, to indicate the extent of the electron deficiency. A carbon atom with 4 electrons is therefore symbolized C 2+ , and a carbon atom with 3 electrons is symbolized C 3+ . If an atom of an element has an excess of an electron, a minus sign is placed after its chemical symbol as a superscript. If there are 2 or more extra electrons, a numeral is included to indicate the extent of the electron surplus. An oxygen atom with 9 electrons (the nucleus has 8 protons) is symbolized O - . An oxygen atom with 10 electrons is symbolized O 2- , and an oxygen atom with 11 electrons is symbolized O 3- . A compound , as well as individual atom, can be ionized. A common example is nitrate, which consists of a nitrogen atom and 3 oxygen atoms (NO 3 ) in the form of an anion; this is symbolized NO 3 - because it normally has a surplus of a single electron. Another example is sulfate, which consists of a sulfur atom and 4 oxygen atoms (SO 4 ), which occurs with an excess of 2 electrons and is symbolized SO 4 2- . Ionized substances often behave differently than when they are not ionized. A common phenomenon is for an electrical insulator (non-conductor) to become electrically conductive when it is ionized. In the Earth's upper atmosphere, ultraviolet radiation from the Sun causes ionization of certain gases. As a result, electromagnetic waves can refracted, and their polarization shifted, at certain frequencies when the waves pass through the gases. This makes long-distance radio communication possible, without the aid of satellites, at some frequencies. The ionization occurs in layers which, taken together, form the Earth's ionosphere .