Isotope

Isotopes are variations of various chemical elements. All isotopes share the same number of protons, but they can and do differ in the amount of neutrons. When an isotope gains an electron it gains a negative charge for each neutron it picks up. If an isotope looses an electron then it gains a positive charge for the each neutron the element gives up.

For example, [|carbon-12], [|carbon-13] and [|carbon-14] are three isotopes of the element [|carbon] with mass numbers 12, 13 and 14 respectively. The [|atomic number] of carbon is 6 which means that every carbon atom has 6 protons, so that the [|neutron numbers] of these isotopes are 6, 7 and 8 respectively.
 * Isotopes** are variants of a particular [|chemical element] . While all isotopes of a given element share the same number of protons, each isotope differs from the others in its number of neutrons. The term isotope is formed from the Greek roots isos (ἴσος "equal") and topos (τόπος "place"). Hence: "the same place," meaning that different isotopes of a single element occupy the same position on the periodic table. The number of protons within the atom's nucleus uniquely identifies an [|element], but a given element may in principle have any number of neutrons. The number of [|nucleons] (protons and neutrons) in the [|nucleus] is the [|mass number] , and each isotope of a given element has a different mass number.