When milk turns sour, it is a ___. A. physical change B. chemical change C. both physical and chemical change D. neither physical nor chemical change 相关知识点: 试题来源: 解析 B。解析:文章中明确提到“When milk turns sour, it is a chemical change.”。
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...
A. chemical reaction B. physical change C. electrical reaction D. biological change 相关知识点: 试题来源: 解析 B。解析:水沸腾是物理变化,只是状态改变,没有新物质生成。选项 A 化学反应会有新物质生成,不符合。选项 C 电反应与题目无关。选项 D 生物变化不符合水沸腾的情况。反馈...
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 ...
百度试题 结果1 题目When iron rusts, it is a: A. Physical change B. Chemical change C. Both physical and chemical change D. None of the above 相关知识点: 试题来源: 解析 B。铁生锈是化学变化,生成了新的物质铁锈。反馈 收藏
A. chemical reaction B. physical change C. biological process D. electrical phenomenon 相关知识点: 试题来源: 解析 B。纸被撕破是一种物理变化,没有新物质生成。选项 A 化学反应会有新物质生成;选项 C 生物过程与纸被撕破无关;选项 D 电现象不符合纸被撕破的情况。反馈...
A. In the case of B. In case C. In case of D. In event of 相关知识点: 试题来源: 解析 A in case of sth.:假使,如果;in case:以防,万一;in event of:如果,以防;三项都不符合题意。in the cause of意为“在,,过程中”。句意:在化学变化中一种新物质生成了。反馈...
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. Wax turns into water B. Wax combines with oxygen to form carbon dioxide and water C. Wax turns into hydrogen gas D. Wax turns into oxygen gas 相关知识点: 试题来源: 解析 B。解析:蜡烛燃烧时,蜡与氧气发生化学反应,生成二氧化碳和水,这是蜡烛燃烧这个化学变化的本质。选项A蜡不会单纯地变成水...
It is not ___ if a new substance is not formed in the change. [ ] A. a physical change B. a chemical change C. a change of state D. a change (2) The dissolving of salt in water is ___. [ ] A. a physical change B. a chemical ...