Chemical reactions often involve changes in substances. Which of the following is an indication of a chemical reaction? A. Change in color B. Change in shape C. Change in size D. Change in position 相关知识点: 试题来源: 解析 A。颜色变化通常是化学反应的标志之一。形状、大小和位置的变化一般...
A. color B. size C. shape D. weight 相关知识点: 试题来源: 解析 A。解析:化学反应经常会有颜色变化。选项 B 尺寸变化一般不是化学反应的主要特征;选项 C 形状变化也不是化学反应常见的特征;选项 D 重量变化不一定在化学反应中普遍发生。反馈 收藏 ...
A. A change in temperature. B. A change in volume. C. A change in mass. D. A change in position. 相关知识点: 试题来源: 解析 A。解析:温度变化是化学反应的一个标志。选项 B 体积变化不一定是化学反应引起的;选项 C 质量变化在一般化学反应中不太明显;选项 D 位置变化与化学反应无关。反馈...
Which of the following is NOT a sign of a chemical reaction? A. Color change B. Temperature rise C. Shape change D. Gas production 相关知识点: 试题来源: 解析 C。本题考查化学反应的标志。颜色变化、温度上升、产生气体都是化学反应的常见标志,形状改变通常不是化学反应的标志。
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
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called Glowee to turn the city into a full-scale bioluminescence laboratory.The goal is to change the way in which cities use light.The company uses marine (海的) bacteria harvested from the coast of France.It makes some of the town's public light up in the cool blue...
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Since you can't look at chemicals at a molecular level with the naked eye, it's helpful to know signs that indicate a reaction has occurred. A chemical reaction is often accompanied by a temperature change, bubbles, color change, and/or precipitate formation. ...
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...