雅思真题听力场景精练 第66期:科技类讲座 生物与化学(3)
日期:2013-07-31 15:50

(单词翻译:单击)

Chemistry is the branch of natural science that studies matter and its composition. How matter reacts, howorganic materials interact and how elements interact are all aspects of chemistry. Basic math concepts are essential to the study of chemistry. Math skills such as addition, subtraction, multiplication and division should already be mastered. Order of operations, or the order in which a complex math problem should be solved, is important to ensure an accurate answer is reached. All matter is made up of molecules. Molecules are represented in text with their elemental names and the number of those molecules in the substance. An example is H2O for water. Water has two hydrogen molecules and one oxygen molecule. A familiartity with the periodoc table will improve the understanding of how specific types of matter can interact. Many sciences have their own terminology. Familiarity with the correct terminology of chemistry will allow you to better understand what is being taught. Chemistry works within several accepted naming conventions. Chemistry frequently studies the three states of matter and how they are affected by variables. Gases, solids and liquids can be combined ina variety of ways to create chemical reactions or new substances entirely. Heat can be applied to substances such as water to change from solid ice to liquid water to gas in the form of stream. A basic knowledge of how matter can change from one state to another is necessary to understand how the addition of chemicals can impact these changes.

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重点单词
  • branchn. 分支,树枝,分店,分部 v. 分支,分岔
  • accurateadj. 准确的,精确的
  • varietyn. 多样,种类,杂耍
  • elementaladj. 元素的,基本的,自然力的 n. 元素
  • essentialn. 要素,要点 adj. 必要的,重要的,本质的
  • impactn. 冲击(力), 冲突,影响(力) vt. 挤入,压紧
  • hydrogenn. 氢
  • moleculen. 分子
  • understandvt. 理解,懂,听说,获悉,将 ... 理解为,认为
  • liquidadj. 液体的,液态的 n. 液体