How to write chemical formulas
For convenience the chemical composition and structure of the chemical preparation of certain rules of chemical formulas with the aid of special characters, symbols have been created, the auxiliary numbers and characters.
Instruction how to write chemical formulas
Chemical formulas of equations are involved in the writing of chemical reactions, a schematic representation of chemical processes, connections. For their use so called spelling language chemistry, which is a collection of symbols such as the symbols of elements, the number of atoms of each element in the described matter and so on.
Symbols of chemical elements - one or more letters of the alphabet, of which the first title. This complete schematic entry naming the element, for example, Ca - calcium is or armor. Calcium.
The number of atoms expressed by mathematical numbers, for example, H_2 - is two hydrogen atoms.
There are several ways to write the chemical formula: simple, empirical, rational and structural. The simplest formula for record reflects the ratio of the chemical elements indicating atomic mass, which is indicated after the symbol of a chemical element as a subscript. For example, H_2O - the simplest formula of a molecule of water, ie, two hydrogen atoms and one oxygen atom.
The empirical chemical formula different from the simple fact that reflects the composition of a substance, but not the structure of the molecules. The formula shows the number of atoms in one molecule, which is also depicted as a subscript.
The difference between the simple and the empirical formula of benzene shows a record of the formula: CH and C_6H_6 respectively. Those. The simplest formula shows a direct correlation of carbon and hydrogen atoms, while empirical said substance in the molecule contains 6 carbon atoms and 6 - hydrogen.
Rational formula clearly shows the presence of groups of atoms of the elements in the compound. These groups are identified by parentheses, and their number is indicated by the subscript after the brackets. The formula also use square brackets that are complexes of atoms (compounds with neutral charged molecule ion).
The structural formula is displayed graphically in two or three dimensions. Chemical bonds between atoms are represented by lines, wherein the atoms specified number of times they play in the joint. Most clearly the substance formula expresses a three-dimensional image, which shows the relative position of the atoms and the distances between them.