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Colors of a single chemical in different solvents, under visible and UV light, showing how the chemical interacts dynamically with its solvent environmentIn addition to the generic definition offered above, there are several niche fields where the term "chemical substance" may take alternate usages that are widely accepted, some of which are outlined in the sections below.
Purification in a chemical context is the physical separation of a chemical substance of interest from foreign or contaminating substances. Pure results of a successful purification process are termed isolate.
It is the only metal to maintain good mechanical properties in air at temperatures above 1,600 °C (2,910 °F). [13] It has the 10th highest boiling point among all elements and becomes a superconductor at temperatures below 0.14 K (−273.010 °C; −459.418 °F).
A chemical element is a chemical substance whose atoms all have the same number of protons.The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus.
Aristotle used the term "substance" (Greek: οὐσία ousia) in a secondary sense for genera and species understood as hylomorphic forms.Primarily, however, he used it with regard to his category of substance, the specimen ("this person" or "this horse") or individual, qua individual, who survives accidental change and in whom the essential properties inhere that define those universals.
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs.
IARC group 3 substances, chemical mixtures and exposure circumstances are those that can not be classified in regard to their carcinogenicity to humans by the International Agency for Research on Cancer (IARC).
Within the sciences, the word "contamination" can take on a variety of subtle differences in meaning, whether the contaminant is a solid or a liquid, [3] as well as the variance of environment the contaminant is found to be in. [2] A contaminant may even be more abstract, as in the case of an unwanted energy source that may interfere with a process. [2]