#### PREDICTING THE CHARGE OF THE ION  THAT WOULD BE PRODUCED BY AN ATOM UTILIZING  THE ATOM’S  NUMBER  OF VALENCE ELECTRONS.

Predicting the charge of an ion.  The charge acquired by an atom when it forms a compound with other atoms is primarily based on its valence electrons (V.E., number of electrons contained in its outer energy level.  The number of .valence electrons can influence whether the atom is most likely to lose electrons or gain electrons.  Atoms with more than 4 electrons, in its valence level, tend to gain additional electrons, thus acquire a negative charge; atoms with less than 4 electrons, in its valence level, tend to lose those electrons, thus acquire a positive charge...

Rational: The most stable valence level (outer energy level) for an atom is one that contains eight electrons. This configuration has the same number of electrons (isoelectronic) with the most stable elements, noble gases.  Atoms with more than 4 electrons strive to gain additional electrons to obtain a total of eight.  Atoms with less than 4 electrons tend to lose their electrons to obtain an "empty" status, so that its next lower level is stable.   Atoms with exactly 4 electrons tend to share electrons.

Example:    Magnesium has 12 electrons and 12 protons; however, it has two electrons in

its valence energy level.  It tends to lose those two electrons so that its next

lower level is stable.  Losing those two electrons, it now has 10 electrons with

its 12 protons. This is a net +2 charge.  It forms an ion with a positive two

charge,   (Mg+2).

Oxygen has 8 electrons with its 8 protons; however, it has 6 electrons in its

valence energy level.  It tends to gain two electrons to obtain eight electrons to

stabilize the valence level.  Gaining two electrons, it now has 10 electrons with

it 8 protons.  This is a net -2 charge.  It forms an ion with a negative two

charge, (O-2).

The Carbon atom (C) atom has four electrons in its valence energy level. It

tends to share electrons when it forms compounds.CF