The phrase "a substance is a" is correct and usable in written English.
It can be used when defining or describing a particular type of substance in a scientific or academic context.
Example: "In chemistry, a substance is a form of matter that has a definite composition and distinct properties."
Alternatives: "a material is a" or "a compound is a".
The exergy of an energy form or a substance is a measure of its usefulness or quality or potential to cause change.
Neurotoxicity occurring as a consequence of a single exposure to a substance is a serious health concern, and incidents of human poisoning have occurred since antiquity.
In other words, some electrical energy is lost as heat (since the temperature of a substance is a measure of how furiously its atoms are vibrating).In 1956 Leon Cooper, an American physicist, figured out that electrons in a superconductor avoid this fate by overcoming their mutual repulsion and pairing up.
An exclusive description of a substance is a description that applies only to that substance.
The new idea is that a substance is a "principle and a cause" (archê kai aitia, 1041a9) of being.
The biodegradability of a substance is a key parameter when considering the environmental implications of its use [1].
Litmus turns red in acidic solutions and blue in alkaline solutions and is the oldest and most commonly used indicator of whether a substance is an acid or a base.
A sufficient description of a substance is an exclusive description that mentions only qualities that make no reference to other substances (Nature of Existence I, sections 101 102).[28] Third, given that each substance must have a sufficient description, the gunkyness of substances implies a contradiction if substances are either material objects or sense-data.
On this view, the sense in which a substance is an entity which does not depend "ontologically" upon anything other than itself is exactly the sense in which it does not depend for its identity upon anything else.
The cell-permeability of a substance is an important characteristic for its in vivo potency.
Because the proliferative effect of natural estrogen is considered the hallmark of estrogen action, it was proposed that this property be used to determine whether a substance is an estrogen.
