Chemical substance is each of the species of matter that makes up the universe.
Chemicals can be classified in two ways: by the type of bond that forms them and by the number of chemicals participating in the bond.
Please find below details about this classification.
As for the type of binding, the substances are classified as ionic, molecular or metallic. The substances ionic have at least one ionic bond. Example:
NaCl (sodium chloride)
NaNO2 (sodium nitrite)
Ionic substances have high boiling and melting points; many of them, when dissolved in water, have their ions separated by water in a process called ion dissociation; conduct electric current in aqueous solution. Follow the table with other examples of ionic substances.
USED IN X-RAY STUDIES IN THE GASTRINTESTINAL TRACT
The substances molecular they are formed exclusively by covalent bonds. In general, they have low boiling and melting temperatures. Most of them do not conduct electricity in aqueous solution. They form molecules. Examples:
Table with other examples of molecular substances:
POISON GAS RESULT OF INCOMPLETE COMBUSTION OF GASOLINE AND ALCOHOL
COMBUSTION REACTION PRODUCT. ABSORBED BY PLANTS FOR USE IN
ALCOHOLIC AND FUEL BEVERAGE INGREDIENT
The substances metallic they are formed exclusively by metallic connections. Examples:
Iron (Fe), Silver (Ag), Gold (Au), Aluminum (Al).
Number of Chemical Elements
As for the number of chemical elements, the substances can be classified as simple or compound.
Simple substance is one formed by a single chemical element.
Ex. Iron (Fe), Aluminum (Al), Hydrogen gas (H2).
SIMPLE SUBSTANCE - IRON
Composite substance is one formed by more than one type of chemical element.
Ex. Sodium Chloride (NaCl), Carbon Monoxide (CO), Water (H2O).
COMPOUND SUBSTANCE - NaCl