2.12 化合物化合物
章节大纲
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What do you need to start building a house?
::你需要什么 开始建造房子?Houses take on a variety of shapes. Some are large mansions while others are simpler dwellings. No matter what the house looks like there will be certain common components – wood, brick, plaster, nails, plumbing, wiring, etc. These components go together in numerous ways to make up the unique final product.
::房屋的形状多种多样。 有些是大型豪宅,而另一些则是更简单的住宅。 无论房屋长什么样 — — 木头、砖头、石膏、钉子、管道、电线等等 — — 都会有一些共同的成分。 这些成分以多种方式组合在一起,组成独特的最终产品。Compounds in chemistry are composed of different types and numbers of atoms. But atoms are common building blocks for a wide variety of compounds, just as brick, wood, and other materials are common building blocks for many types of houses.
::化学中的化合物由不同种类和数目的原子组成,但原子是各种化合物的常见构件,就像砖块、木头和其他材料是许多类型房屋的共同构件一样。Compounds
::化合物A compound is a substance that contains two or more chemically combined in a fixed proportion. The elements carbon and hydrogen combine to form many different compounds. One of the simplest is called methane, in which there are always four times as many hydrogen particles as carbon particles. Methane is a because it always has the same composition. However, it is not an element because it can be broken down into simpler substances – carbon and hydrogen.
::一种化合物是一种含有两种或两种以上以固定比例化学组合的物质。 元素碳和氢组成了多种不同的化合物。 最简单的一种是甲烷,其中的氢粒子总比碳粒子多四倍。 甲烷是因为它的成分总是相同。 然而,它不是一个元素,因为它可以分为更简单的物质 — — 碳和氢。Recall that the components of a can be separated from one another by physical means. This is not true for a compound. Table salt is a compound consisting of equal parts of the elements sodium and chlorine. Salt cannot be separated into its two elements by filtering, distillation , or any other physical process. Salt and other compounds can only be decomposed into their elements by a chemical process. A is a change that produces matter with a different composition. Many compounds can be decomposed into their elements by heating. When sugar is heated, it decomposes to carbon and water. Water is still a compound, but one which cannot be broken down into hydrogen and oxygen by heating. Instead, the passage of an electrical current through water will produce hydrogen and oxygen .
::回顾一个化合物的成分可以通过物理手段相互分离。对于化合物来说,情况并非如此。表盐是由钠和氯等元素构成的化合物。盐不能通过过滤、蒸馏或任何其他物理过程分离成两个元素。盐和其他化合物只能通过化学过程分解成其元素。A是产生不同成分的物质的改变。许多化合物可以通过加热分解成其元素。当加热时,糖会分解成碳和水。水仍然是一个化合物,但不能通过加热分解成氢和氧。相反,通过水通电流会产生氢和氧。The properties of compounds are generally very different than the properties of the elements from which the compound is formed. Sodium is an extremely reactive soft metal that cannot be exposed to air or water. Chlorine is a deadly gas. The compound sodium chloride is a white solid which is essential for all living things ( Figure ).
::化合物的特性通常与构成化合物的元素的特性大不相同。 钠是一种极具反应性的软金属,不能接触空气或水。 氯是一种致命气体。 氯化钠化合物是一种白色固体,对所有生物都至关重要(图 )。(A) Sodium is so reactive that it must be stored under oil. (B) Chlorine is a poisonous yellow-green gas. (C) Salt crystals, a compound of sodium and chlorine Science Friday: Celebrating Explosive Chemistry
::科学星期五:庆祝爆炸性化学July Fourth: A day for picnics, parades and chemistry. In this video by Science Friday, Professor Bassam Shakhashiri explains some of the science of fireworks.
::7月4日:野餐、游行和化学日,Summary
::摘要-
A compound is a substance that contains two or more elements chemically combined in a fixed proportion.
::化合物是指含有两个或两个以上元素的物质,按化学方式将元素以固定比例结合。 -
A chemical change is a change that produces matter with a different composition.
::化学变化是一种产生不同成分物质的变化。
Review
::回顾-
What is a compound?
::什么是复合物? -
How is a compound different from an element?
::化合物与元素有何不同? -
What is a chemical change?
::什么是化学变化?
Explore More
::探索更多Use the resource below to answer the following questions.
::使用以下资源回答下列问题。-
What lists all the elements we know about?
::我们所知道的所有元素清单是什么? -
What compound is made of two hydrogen atoms and one oxygen atom?
::两个氢原子和一个氧原子构成什么化合物? -
What compound is made of one carbon atom and two oxygen atoms?
::一个碳原子和两个氧原子构成什么化合物?
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A compound is a substance that contains two or more elements chemically combined in a fixed proportion.
