Pure Substance definition is that, it is a material that is homogeneous or has constant composition. Throughout the sample, a pure substance or chemical substance has constant properties. Chemical elements and chemical compounds are pure substances. All elements are pure substance. Examples of chemical elements that are pure substances are tin, sulphur, and diamond. Chemical compounds on the other hand that are pure substances include water, salt, sugar, gold, and baking soda. Example, for pure water, it has the same properties and the same ratio of hydrogen to oxygen. Pure water is composed of 2 hydrogen atoms and 1 oxygen atom which are bonded chemically. Pure water us an example of pure substance definition because distilling it will not separate water into its components which are hydrogen and oxygen. Instead, it will only produce water vapor. For pure gold on the other hand is composed only of 1 pure gold atom. Pure substance definition is explained more by theses example. The chemical or pure substance definition is clear, all elements are pure substances. This is because they have no impurities and are not combined yet to other elements or compounds. A compound on the other hand is a combination of 2 or more elements. But even if it is a combination of elements, this combination of elements or compounds can no longer be separated into 2 or more substances. Another example of a compound pure substance is a salt. Salt is a mixture Sodium and Chlorine. Even through sifting, decantation, visual sorting, magnetic attraction, separating funnel, filtration, evaporation, crystallization, distillation, or other physical and mechanical ways are applied to the salt, the 2 elements cannot be separated. Scientists have found out that there were certain basic substances found in all materials. These substances which are also referred as “building blocks of matter” are called elements. All of these are pure substances which cannot be broken down to simpler substances. Compounds, as explained above, are substances that are made by combination of 2 or more elements. Other pure substance definition is a sample of matter, whether an element or compound, which composed of one component. The element or compound should have definite chemical and physical properties and composition. A pure substance cannot be separated into 2 or more substances by mechanical or physical method like filtering, crystallization, sifting, distillation, and other means. Additional pure substance definition is that its properties do not rely on how it is purified or prepared. It has constant chemical composition and the properties are always constant. But, there is also exemption to this pure substance definition. There is pure substance that can be defined as a form of matter that has both distinct properties and definite composition. There are several alloys that have uncertain composition. Chemical or pure substance displays sharp boiling and melting point. Based on the pure substance definition, it also has constant density, color, and appearance throughout the sample. But for some, homogenous mixtures like vegetable oil, air, and honey are also considered based on pure substance definition. http://puresubstance.org/pure-substance-definition- exposed/
"Pure Substance Definition"