Bottle of solution of sodium dodecyl sulfate for use in the laboratory. The critical micelle concentration (CMC) in pure water at 25 Â°C is 8.2 mM, and the aggregation number at this concentration is usually considered to be about 62. The micelle ionization fraction (Î±) is around 0.3 (or 30%).
Definition: A pure substance is a sample of matter with both definite and constant composition with distinct chemical properties.
An element is any substance that consists of only one type of atom, that is all atoms have the same number of protons. A compound is a substance that has two or more element â¦ s chemically bonded together either covalently or ionically in a fixed ratio.n element is a pure substance composed of 1 type of atom. Meaning all the atoms have the same number of protons. A compound is a pure substance composed of 2 or more types â¦ of atom chemically bonded together.