What is a compound
In chemistry, a compound is defined as the substance resulting from the combination of two or more elements according to a well-defined quantitative relationship.
This ratio not only indicates the amount of elements present in the compound, but also indicates the numerical ratio between the atoms present in the compound.
This is the reason why the composition that characterizes each compound is and must otherwise be rigidly constant. except in rare cases one could not speak of compound.
It is said to be an organ resulting from the meeting of several organs or similar elements: leaf c.,
Formed by several leaflets, (as in the grasshopper and horse chestnut); Inflorescence c. When its axis is branched and bears secondary inflorescences.
Substance with a defined chemical composition resulting from the union of two or more different elements.
The combination of the different elements that react to form ac occurs according to established laws (of certain proportions, of several proportions, of combinations of weights, etc .; Combination).
Most of the c. it is of synthetic origin. NS. they are divided into inorganic and organic: the first are those that do not contain carbon atoms in their molecule
(except carbon monoxide, carbon dioxide, carbonates, carbides, also classified as inorganic); NS.
On the other hand, those that result less frequently from the combination of carbon with hydrogen alone or together with other elements such as oxygen, nitrogen, sulfur and others are organic.
They are defined as:
c. asymmetric if they contain one or more asymmetric and optically active carbon atoms; C. binary, ternary, quaternary, when the molecules are formed by atoms of two or three or four different species;
A non stoichiometric, such as c. intermetallic compounds (➔ intermetallic compounds, compounds) to which the constant composition law does not apply;
B Molecular or addition, those formed by the union of two or more molecules of different substances; C.
unsaturated, class of c. Chemically similar homologues (ie they belong to the same series) but differ from each other by a constant quantity (such as -CH2-):
eg. B. methane (CH4), ethane (C2H6), propane (C3H8) etc .; c) organometallic (or organometallic),
class of c. organic, in which one or more carbon atoms are bonded to metal atoms (magnesium, cobalt, iron, zinc, etc.);
Saturated, grade of c. organic, which contain only single bonds, or those in which the valences of the carbon atoms are all saturated and therefore do not contain double or triple bonds.