Every day we handle many substances which are chemicals, and we even consume them. Table salt (NaCl), sugar, vinegar are a few chemical substances used in our daily routine. Therefore, to have a clear understanding, one must know what exactly a chemical means and its composition.
What is Chemical Composition?
Chemical composition can be defined as the arrangement, ratio, and type of atoms in molecules of chemical substances. The chemical composition will vary if chemicals are subtracted or added from a substance. That is when the ratio of the substance changes or when chemical changes occur in the chemicals.
It is the chemical composition of a substance that determines the properties of the substance. We can conclude from here that the way atoms are put together, the density, colour, strength and other properties are determined.
Chemical Composition of Substances
Any substance which has a clear and specific chemical composition and structure is known as a chemical. Chemicals exist in a range of states i.e. they can be either solid or liquid. They can change their state influenced by certain factors like pressure, temperature etc.
The chemist Joseph Proust paved the fundamental of modern chemistry known as Law of constant composition. A chemical substance has a fixed composition. According to Proust’s inference, “All samples of a compound have the same composition; i.e., all samples have the same proportion, by mass, of the elements present in the compound”. For instance, water is a chemical compound made up of two elements hydrogen (H) and oxygen (O) in a definite ratio. The purified water samples from a bore-well and a sea will also have the same compositions in the same ratio.
Atom is the basic unit of chemical substances which consist of subatomic particles such as electrons, neutrons, and protons. An element is composed of the same atom. These can’t be fragmented by simple or ordinary processes. Metals, non-metals, and metalloids are three classifications of elements. Physical properties, chemical properties, and stability are a few criteria for the classification. At last, elements (two or more) combine to form a chemical compound. When two or more atoms combine, a molecule is formed. For example, water (H2O), N2O etc are compounds while N2, O2, H2O are molecules. Hence, it is said that every compound is a molecule but every molecule is not a compound.
As we have seen, chemical substances have a fixed composition; they also have a chemical name and formulae based on their composition. Chemists follow the International Union of Pure and Applied Chemistry (IUPAC) or the Chemical Abstracts Service (CAS) rules for naming a compound. At certain occasions, chemical compounds obtained have mixed impurities. A purification process might be either a physical or a chemical process.
Stay tuned with BYJU’S to learn more interesting topics in Chemistry. Also, get various engaging and interactive video lessons to learn more effectively.