Chemical substance identity of benzene, until the correct structure was described by Friedrich August Kekulé. Likewise, the idea of stereoisomerism – that atoms have rigid three-dimensional structure and can thus form isomers that differ only in their three-dimensional arrangement – was another crucial step in understanding the concept of distinct chemical substances. For example, tartaric acid has three distinct isomers, a pair of diastereomers with one diastereomer forming two enantiomers. An element is a chemical substance made up of a particular kind of atom and hence cannot be broken down or transformed by a chemical reaction into a different element, though it
Chemical endangerment Chemical endangerment Chemical endangerment is the crime of exposing a child to a controlled substance or an environment in which it is produced. It was added to the Alabama legal code in 2006, with the intention of protecting children from methamphetamine laboratories. Since then, it has been used to prosecute women who give birth to children that test positive for harmful drugs and also THC, the active ingredient in marijuana. Section 26-15-3.2 of the Alabama legal code discusses the crime of "chemical endangerment of exposing a child to an environment in which controlled substances are produced or distributed." It is