Most atoms execute not have actually eight electrons in your valence electron shell. Some atoms have actually only a few electrons in their outer shell, while part atoms lack only one or 2 electrons to have an octet. In situations where an atom has actually three or under valence electrons, the atom may lose those valence electron quite easily until what stays is a lower shell that consists of an octet. Atoms that lose electrons get a hopeful charge as a resultbecause they are left through fewer negatively fee electrons to balance the hopeful charges that the protons in the nucleus. Positive charged ions are referred to as cations. Many metals end up being cations as soon as they make ionic compounds.

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Cations

A neutral salt atom is most likely to accomplish an octet in that is outermost covering by losing its one valence electron.

The cation developed in this way, Na+, is referred to as the salt ion to distinguish it native the element. The outermost covering of the sodium ion is the second electron shell, which has actually eight electron in it. The octet rule has to be satisfied. Number (PageIndex1) is a graphical explicate of this process.

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api/deki/files/114134/3.2B.jpg?revision=1" />Figure (PageIndex2): The formation of a Chlorine Ion. On the left, the chlorine atom has actually 17 electrons. ~ above the right, the chloride ion has 18 electrons and has a 1− charge.

The surname for positive and an unfavorable ions space pronounced CAT-eye-ons and also ANN-eye-ons, respectively.

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In countless cases, elements that belong to the same team (vertical column) top top the periodic table form ions with the very same charge because they have actually the same variety of valence electrons. Thus, the regular table i do not care a tool for psychic the fees on many ions. For example, all ion made native alkali metals, the first column top top the periodic table, have actually a 1+ charge. Ions made indigenous alkaline planet metals, the second group on the regular table, have a 2+ charge. ~ above the other side the the routine table, the next-to-last column, the halogens, kind ions having a 1− charge. Figure (PageIndex3) shows just how the charge on many ions have the right to be guess by the location of an element on the routine table. Note the convention of an initial writing the number and then the authorize on a ion through multiple charges. The barium cation is created Ba2+, no Ba+2.