What Does tetravalence Mean
The concept of tetravalence is not accepted by the Royal Spanish Academy ( RAE ). On the other hand, the term tetravalent does appear in the dictionary , an adjective that refers to that which, in the field of chemistry, has four valences .
Remember that valence is the number that reveals how an atom can combine with others to form a compound. This is because the valence indicates the amount of electrons that a chemical element has when forming a bond with another. The valence also reflects the oxidation number of the element.
The oxidation number (also called oxidation state ) is an integer that serves to represent the amount of electrons that an atom receives or that it provides to others so that they have them available when forming a certain compound, and this expressed with a minus sign or a plus sign , respectively.
In other words, if this number is positive, then the atom loses or shares electrons (the latter takes place if there is a second atom, which is capable of capturing them). In the same way, a negative oxidation number indicates that the atom gains electrons, or that it shares them with one that tends to give them up. Roman numerals are used to write this indicative value, preceded by the corresponding sign.
Tetravalence thus indicates that the chemical element has a tendency to bond through four covalent bonds. This particularity is associated with the tetrahedral structure of the molecules .
Molecules with this structure have a geometry such that there is an atom in the center and it is chemically bonded with four substituents, one at each corner of a tetrahedron . Importantly one substituent is a functional group , alkyl group or hetero atom , in a hydrocarbon, occupies the position of a hydrogen atom or a group the outgoing speaking of any organic compound. Among the chemical species that represent this type of tetrahedral geometry are the ammonium ion , phosphate and methane .
It can be said, in other words, that tetravalence indicates that an element has four valences : that is, four bonds . Among the elements that have tetravalence is carbon .
Thanks to its tetravalence, carbon has a wide combining capacity . Its atoms, therefore, can be linked in complex structures since they have a four-fold chance of establishing bonds.
These four bonds are located symmetrically in space , going to the lines that link the nucleus of the tetrahedron with its vertices. Today some 16 million carbon compounds are known.
It is called vaccine quadrivalent flu , on the other hand, one that protects against four different types of this virus : two influenza A and two from B . Previously, and for several years, the vaccine was trivalent, since it only protected against three types of influenza: an A H1N1 virus , an A H3N2 virus and a B virus . Although in most flu seasons there are two of the most common B viruses , initially scientists could only choose one of them.
Needless to say, the advances that made it possible to convert the trivalent vaccine to quadrivalent made it a much more effective option. Although the name is the same in all cases, it comes in six different versions, depending on the age group; on the other hand, there are also variations for people with certain factors, such as allergies or specific health problems.