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4 days ago · electron, one of the three basic subatomic particles —along with protons and neutrons —that make up atoms, the basic building blocks of all matter and chemistry . The negatively charged electrons circle an atom’s central nucleus, which is formed by positively charged protons and the electrically neutral particles called neutrons.
May 3, 2024 · EPA finalized changes to the small manufacturer definition and the addition of a small government definition. Manufacturers meeting the small manufacturer or small government definition have no or reduced reporting obligations under CDR, unless the manufactured (including imported) chemical is the subject of certain TSCA actions .
May 2, 2024 · periodic table, in chemistry, the organized array of all the chemical elements in order of increasing atomic number —i.e., the total number of protons in the atomic nucleus. When the chemical elements are thus arranged, there is a recurring pattern called the “periodic law” in their properties, in which elements in the same column (group ...
May 10, 2024 · distillation, process involving the conversion of a liquid into vapour that is subsequently condensed back to liquid form. It is exemplified at its simplest when steam from a kettle becomes deposited as drops of distilled water on a cold surface. Distillation is used to separate liquids from nonvolatile solids, as in the separation of alcoholic ...
22 hours ago · Chemical incompatibilities: Chemical incompatibilities occur when two or more substances react chemically to produce a new substance that can be harmful to the patient. Examples of chemical incompatibilities include the formation of precipitates, degradation of active ingredients, and the formation of toxic by-products.
May 14, 2024 · Anthony J.F. Griffiths. Mutation, an alteration in the genetic material (the genome) of a cell of a living organism or of a virus that is more or less permanent and that can be transmitted to the cell’s or the virus’s descendants. The genomes of organisms are all composed of DNA, whereas viral genomes can be of DNA or RNA.
May 12, 2024 · Drug, any chemical substance that affects the functioning of living things and the organisms (such as bacteria, fungi, and viruses) that infect them. Pharmacology, the science of drugs, deals with all aspects of drugs in medicine, including their mechanism of action, physical and chemical.
