Valence
 
Atoms make bonds with other atoms to form molecules. The number of bonds that an atom of an element makes with other atoms is the valence of that element.


The first row of the periodic table contains two elements, hydrogen and helium. Hydrogen has a valence of one. Helium has a valence of zero.


The second row of the periodic table contains eight elements. The valences of these eight elements, in order, are:


1,   2,   3,   4,   3,   2,   1,   0


Boron is element five. A boron-10 atom is made up of five deutons.  Boron has a valence of three. At the middle of a boron-10 atom is a pair of deutons.  The other three deutons surround the pair of deutons. These three deutons each make one bond with another atom.


Carbon is element six. A carbon-12 atom is made up of six deutons.  Carbon has a valence of four. At the middle of a carbon-12 atom is a pair of deutons.  The other four deutons surround the pair of deutons. These four deutons each make one bond with another atom.


Nitrogen is element seven. A nitrogen-14 atom is made up of seven deutons. Nitrogen has a valence of three. At the middle of a nitrogen-14 atom is a pair of deutons.  Surrounding this pair of deutons are three single deutons and a pair of deutons. The three single deutons each make one bond with another atom.


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