Which of the following is a chemical reaction? A. Melting ice B. Breaking a glass C. Rusting of iron D. Folding a paper 相关知识点: 试题来源: 解析 C。本题考查化学反应的定义。A 选项冰融化是物理变化,物质的状态发生改变但没有新物质生成。B 选项打破玻璃也是物理变化,只是物质的形状发生改变...
Which of the following is a chemical reaction? A. Melting ice B. Breaking a glass C. Rusting of iron D. Folding a piece of paper 相关知识点: 试题来源: 解析 C。本题主要考查化学变化的定义。A 选项冰融化是物理变化,物质的状态改变但没有新物质生成。B 选项打破玻璃也是物理变化,只是物质的...
In environmental protection,chemical reactions play an important role.Which of the following is a chemical reaction that can help reduce air pollution? A. Burning coal B. Planting trees C. Photo catalysis D. Dumping waste 相关知识点:
Chemical properties determine the behavior of substances. Which of the following is a chemical property that affects the reactivity of a substance? A. Color B. Melting point C. Solubility D. Electronegativity 相关知识点: 试题来源: 解析 D。电负性影响物质的反应性,是化学性质。颜色、熔点和溶解性...
百度试题 结果1 题目Which of the following is a common chemical used in making soap? A. Salt B. Sugar C. Lye D. Vinegar 相关知识点: 试题来源: 解析 C。碱液(Lye)是制作肥皂常用的化学物质。选项 A 盐;选项 B 糖;选项 D 醋。反馈 收藏 ...
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 收藏 ...
A. It is static. B. It is not affected by temperature. C. It is not affected by concentration. D. It is dynamic. 相关知识点: 试题来源: 解析 D。原因:文中提到 One of the characteristics of chemical equilibrium is that it is dynamic.反馈...
A. Noise pollution B. Air pollution caused by factories C. Littering D. Overfishing 相关知识点: 试题来源: 解析 B。本题主要考查对化学污染的理解。选项 A 噪音污染不属于化学污染。选项 B 工厂造成的空气污染通常涉及化学物质的排放,是化学污染的一种。选项 C 乱扔垃圾主要是固体废弃物污染,不一定直接涉...
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...
百度试题 结果1 题目Which of the following is an example of a chemical change? A. Melting ice B. Breaking a glass C. Burning wood D. Folding a paper 相关知识点: 试题来源: 解析 C。燃烧木材会产生新的物质,属于化学变化。反馈 收藏