(chemistry) a substance used in or produced by a reaction that changes atoms or molecules
化学物质
the parts or elements that something consists of and the way they are combined
组成, 成分
a pure substance formed from two or more chemical elements chemically bonded in fixed proportions
化合物
derived from, produced by, or relating to living organisms
有机, 生物的
describing chemical compounds that do not contain carbon-hydrogen bonds and are typically derived from minerals or non-living matter
无机的
铁和铜等金属是对工业应用至关重要的无机元素的例子。
a liquid that is capable of dissolving another substance
溶剂, 溶媒
氯仿由于其非极性性质，可作为脂类、脂肪和蜡的有效溶剂。
a substance that is dissolved in a solvent, resulting in a solution
溶质, 溶解物质
当糖（蔗糖）加入咖啡时，糖作为溶质溶解在咖啡（溶剂）中。
(of a substance) able to break up and disperse within a fluid
可溶的
甘油可混溶且在许多极性溶剂中溶解，但不会溶解在油等非极性液体中。
unable to be dissolved, especially in a liquid
不溶的, 难溶的
尽管搅拌，粉末仍然不溶。
a mixture of different liquids
溶液, 混合物
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, leading to variation in atomic mass
同位素, 同位素形式
氘和氚是氢的同位素，因其中子数不同而有所区别。
a combination of two or more metals, creating a metal that is usually stronger or more resistant
合金
黄铜是铜和锌的合金，常用于管道装置和乐器中。
a compound with a hydroxyl group (-OH) attached to a carbon atom, widely used as solvents, fuels, and in pharmaceutical and chemical synthesis
酒精, 乙醇
(chemistry) a dark liquid from underground, made of hydrocarbons, used to make fuel and plastic
石油
(chemistry) a compound made when the hydrogen in an acid is replaced by a metal or a metal-like group
盐
a hard alloy consisting mainly of copper and tin
青铜
a type of hard metal that is made of a mixture of iron and carbon, used in construction of buildings, vehicles, etc.
钢, 硬金属
(chemistry) a soft, gray-black form of carbon used as a lubricant and as a moderator in nuclear reactors
石墨, 筆鉛
a usually solid and hard substance that heat and electricity can move through, such as gold, iron, etc.
金属
made of or resembling metal
金属的, 似金属的
航天器的金属外壳保护它免受外层空间的恶劣条件影响。
(chemistry) a salt or ester of sulfurous acid used as a preservative in foods and wines
亚硫酸盐
a numerical measure of how acidic or basic a solution is, based on hydrogen-ion activity
pH, 酸碱度
any water-soluble compound that can turn litmus blue and reacts with an acid to form a salt and water
碱, 碱
像碳酸钾这样的碱被用于化学实验室中中和酸。
(chemistry) a substance that can accept protons, donate electrons, or release hydroxide ions in aqueous solution
碱
a water-soluble chemical substance that contains Hydrogen and has a sour taste or corrosive feature with a PH less than 7
酸, 酸性物质
the level of acid in a substance, often measured by a pH below 7
酸度, 酸性水平
雨後水的酸度增加了。
(chemistry) able to act as either an acid or a base depending on the conditions
两性的, 酸碱两性的
the gradual destruction of materials by chemical reaction, usually of metals
腐蚀
定期维护对于防止腐蚀和延长金属结构的使用寿命是必要的。
to heat a liquid and turn it into gas then cool it and make it liquid again in order to purify it
蒸馏, 通过蒸馏净化
精油是从各种芳香植物中蒸馏出来的。
a fundamental unit in chemistry that represents the amount of substance containing as many entities (atoms, molecules) as there are in 12 grams of carbon-12
摩尔, 物质的量
(chemistry) to become separated from the solvent in a solid form
沉淀
冷却饱和糖溶液时，晶体开始在容器底部沉淀。
having a tendency to change rapidly and unpredictably, often characterized by fluctuations or instability
易变的, 不稳定的
这种化学化合物是挥发性的，需要小心处理。
a solution containing a weak acid and its conjugate base, or a weak base and its conjugate acid, which maintains a stable pH when small amounts of acid or base are added
缓冲液, 缓冲溶液
缓冲液在生物系统中对于维持酶活性所需的pH至关重要。
a solution of ammonia gas dissolved in water, commonly called aqueous ammonia
氨水,氨溶液
水性氨比气态氨的刺激性更小。
to become incorporated into a liquid and form a solution
溶解, 溶化
