Lewis acids and bases studied chemical bonding. In 1923, Lewis wrote "An acid substance is one which can employ an electron lone pair from another molecule in completing the stable group of one of its own atoms." The Brønsted–Lowry acid–base theory was published in the same year. The two theories are distinct but complementary. A Lewis base is also a Brønsted–Lowry base, but a Lewis acid doesn't need to be a Brønsted–Lowry acid. The classification into hard and soft acids and bases (HSAB theory) followed in 1963. The strength of Lewis acid-base interactions, as measured by the standard enthalpy of formation of an adduct
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