When iron rusts, it is a chemical change. What happens during this process? A. The color remains the same. B. No chemical reaction occurs. C. A new substance is formed. D. The mass of iron decreases. 相关知识点: 试题来源: 解析 C。铁生锈是化学变化,在这个过程中会形成新物质。A ...
Izquierdo, MerceSolsona, N. What is conserved in a chemical change? Opinions of secondary school pupils. in Proceedings of the Third International Seminar on Misconceptions and Educational Strategies in Science and Mathematics. 1993. Ithaca, New York: Cornell University....
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...
What happens to matter during a chemical reaction? Reactions: There are two general types of changes, physical and chemical. Both involve energy transfer and changes to the matter. We can determine if a change is physical or chemical based on what exists after the reaction. ...
A. No change in properties. B. Formation of a salt and water. C. Only a physical mixture is formed. D. The acid and base remain unchanged. 相关知识点: 试题来源: 解析 B。酸碱反应是化学变化,会生成盐和水。A 选项性质会改变,错误;C 选项不是物理混合,错误;D 选项酸和碱会发生反应改变,错...
After adding the chemical, we observed a change. What might be the next step? A. Add more chemicals. B. Write down the observation. C. Repeat the step. D. Do nothing. 相关知识点: 试题来源: 解析 B。解析:观察到变化后应该记录观察结果。A 选项添加更多化学物质可能会使实验失去控制;C 选项...
how a chemical change is 27.It is hard to explainA.what is a chemical changeB.what a chemical change isC.how is a chemical changeD.how a chemical change is 37.It is hard to explainA.what is a chemical changeB.what a chemical change isC.how is a chemical changeD.how a chemical...
A.that 定语从句.that something is changed into a thing different from what it was 修饰 a process. 分析总结。 athatbwhichcwhendwhat到底是定语从句还是同位语从句呀我快被搞疯了结果一 题目 a chemical change is a process---something is changed into a thing different from what it wasA that B...
Which of an atom's electrons are involved in chemical reactions? What occurs when an atom loses an electron? Which chemicals change sea water's colour? What happens during a chemical pregnancy? What happens after a chemical pregnancy?
What occurs during a decomposition reaction?Chemical ReactionsChemical reactions occur when substances interact in a way that changes their electron arrangement. There are five general chemical reactions. The transfer of energy is associated with chemical reactions....