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On 31 July 1931, Austin M. Patterson, the dictionary's chemistry editor, sent in a slip reading "D or d, cont./density." This was intended to add "density" to the existing list of words that the letter "D" can abbreviate. The phrase "D or d" was misinterpreted as a single, run-together word: Dord. This was a plausible mistake because headwords ...
This glossary of chemistry terms is a list of terms and definitions relevant to chemistry, including chemical laws, diagrams and formulae, laboratory tools, glassware, and equipment. Chemistry is a physical science concerned with the composition, structure, and properties of matter , as well as the changes it undergoes during chemical reactions ...
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density. An example of a physical change is the process of tempering steel to
In physics, chemistry, and other related fields like biology, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma.
In general, as temperature decreases from 25 °C to 5 °C the pH of a tris buffer will increase an average of 0.03 units per degree. As temperature rises from 25 °C to 37 °C, the pH of a tris buffer will decrease an average of 0.025 units per degree.
While the term chemical substance is a precise technical term that is synonymous with chemical for chemists, the word chemical is used in general usage to refer to both (pure) chemical substances and mixtures (often called compounds), [14] and especially when produced or purified in a laboratory or an industrial process.
Physical or chemical properties of materials and systems can often be categorized as being either intensive or extensive, according to how the property changes when the size (or extent) of the system changes. The terms "intensive and extensive quantities" were introduced into physics by German mathematician Georg Helm in 1898, and by American ...
[1] [2]: 86 [3]: 3 Examples of physical properties include density, index of refraction, magnetization and chemical composition. The term phase is sometimes used as a synonym for state of matter , but there can be several immiscible phases of the same state of matter (as where oil and water separate into distinct phases, both in the liquid state).