Matter (物质) is always changing,either physically or chemically.If a material goes through a physical change,it is still the same material.During a chemical change,one kind of matter changes into another completely different kind of matter.For example,when we burn wood or cook fish,materials ...
A. a chemical change is always faster. B. a physical change does not change the appearance of a substance. C. a chemical change produces new substances. D. a physical change always requires heat. 相关知识点: 试题来源: 解析 C。解析:化学变化和物理变化的区别是化学变化产生新物质。A 不一定...
What does a color change indicate the formation of in chemistry? What is the chemical reaction of oxygen with other substances? What are chemical laws? What metal can replace another metal in a reaction? What is the name given to an atom that gains or loses electrons in a chemical reaction...
A chemical change is different from a physical change because in a chemical change ___. A. the appearance changes B. the composition changes C. the size changes D. the weight changes 相关知识点: 试题来源: 解析 B。化学变化与物理变化不同在于化学变化中物质的组成发生了变化。反馈 ...
阅读理解2Do you like physics or chemistry? Matter(物质) is1. The material doesn't change when wealways changing, either physically or chemically. If amaterial goes through a physical change, t is stil thesame materia. During a chemical change, one kind ofA. meltice cream B. burn papermat...
百度试题 结果1 题目What is the difference between a chemical reaction and a physical change?相关知识点: 试题来源: 解析 Chemical changes produce new substances,not a physical change 反馈 收藏
a change (2) The dissolving of salt in water is ___. [ ] A. a physical change B. a chemical change C. hydrogen and oxygen D. breaking up (3) The change of the three states of water is ___. [ ] A. a chemical change B. different substances...
Chemical sunscreens, on the other hand, work like a sponge by absorbing UV rays into the skin.Once absorbed, they change harmful UV rays to heat (a less harmful form of energy), then disperse them through the skin. Formulations that contain both mineral and chemical ingredients are termed ch...
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ait is generally recommended to routinely test for changes in chemical and physical properties such as discolouration, viscosity and odour, for each indibidual matrix system, as well as the effects of external factors such as ph,moisture and UV light. 一般推荐它定期测试对于在化工和有形资产上的...