Oregon Department of Human Services / Seniors & People with Disabilities / Intellectual and Developmental Disabilities.
Note [Deprecated. The linear element defines the value of a param element at a particular time, relative to the start of the transition or effect that contains the param element. The linear element causes the parameter to make a smooth transition from its previous value to the new value. For an instantaneous jump to a new value, use the at element. Attributes.
For a pure substance or a solvent in a condensed state (a liquid or a solid): the standard state is the pure liquid or solid under a pressure of 1 atm. For an element: the form in which the element is most stable under 1 atm of pressure. One exception is phosphorus, for which the most stable form at 1 atm is black phosphorus, but white phosphorus is chosen as the standard reference state for zero enthalpy of formation.