| 单词 | activity |
| 释义 | activity 1 Symbol a. A thermodynamic function used in place of concentration in equilibrium constants for reactions involving nonideal gases and solutions. For example, in a reaction A ? B + C the true equilibrium constant is given by K = aBaC/aA where aA, aB, and aC are the activities of the components, which function as concentrations (or pressures) corrected for nonideal behaviour. Activity coefficients (symbol γ) are defined for gases by γ = a/p (where p is pressure) and for solutions by γ = aX (where X is the mole fraction). Thus, the equilibrium constant of a gas reaction has the form Kp =γBPBγCPC/γAPA The equilibrium constant of a reaction in solution is Kc = γBXBγC/γAXA The activity coefficients thus act as correction factors for the pressures or concentrations. See fugacity.2 Symbol A. The number of atoms of a radioactive substance that disintegrate per unit time. The specific activity (a) is the activity per unit mass of a pure radioisotope. See radiation units. |
| 随便看 |
|
物理辞典收录了3346条物理词条，基本涵盖了常用物理知识及物理英语单词词组的翻译及用法，是物理学习的有利工具。