When matter is changed to a substance different from what it was , the change is a chemical change 当物质变成与其原来不一样的另一物质时，这种变化是化学变化。
Modelling results are subsequently analysed for the pollutant transport pathways and their chemical transformations 最后，对模拟结果进行分析，以检讨污染物的转移动向及其化学变化。
Modelling results are subsequently analysed for the pollutant transport pathways and their chemical transformations 最后，对模拟结果进行分析，以检讨污染物的转移动向及其化学变化。
This ionization process often results in chemical changes in living tissues , which can lead to injury in the organism 这个电离过程通常会引致生物组织产生化学变化，因而对生物构成伤害。
This ionization process often results in chemical changes in living tissues , which can lead to injury in the organism 这个电离过程通常会引致生物组织产生化学变化，因而对生物构成伤害。
Any change which alters the chemical properties of a substance is a chemical change . for example , the rusting of iron is a chemical reaction 任何改变物质化学性质的变化都是化学变化。例如，铁钉的生锈就是一种化学变化。
We may define chemistry as the science in which we deal with the chemical change in matter as a result of which it is possible to form a new substance 我们可以定义化学为科学,在化学中,我们处理化学变化,结果是这种变化写可能形成新的物质
We may define chemistry as the science in which we deal with the chemical change in matter as a result of which it is possible to form a new stance 我们将化学定义为：在人们中，处理物质间化学变化，并且此变化可能会产生一个新物质的科学家。
We may define chemistry as the science in which we deal with the chemical change in matter as result of which it is possible to form a new substance 译文：我们可以说化学是一种论述物质的化学变化的科学，而且通过这种变化还能形成一种新的物质。
For these creatures to become oil , it was necessary that they should be imprisoned between layers of rock for an enormous length of time 上面覆盖着大量沉积的泥沙，通过一系列化学变化、压力和温度的影响，经过漫长的岁月，变成了现在我们所说的石油。
