Which of the following is a chemical change? A. Melting ice B. Breaking a glass C. Burning wood D. Crushing a can 相关知识点: 试题来源: 解析 C。燃烧木材是化学变化。选项 A 冰融化是物理变化;选项 B 打破玻璃是物理变化;选项 D 压扁罐子是物理变化。反馈 收藏
Chemical reactions involve formation of new chemical substances from the reactants. These involve chemical changes since the chemical composition of the reactants changes when they are converted to the products.Answer and Explanation: Melting of ice is not a chemical reaction but a physical ...
Is snow melting a physical or chemical change? Once the snow is brought inside or the temperature rises, the snow begins to melt, and those tightly packed molecules become loosely packed molecules in water. Placing the containers in a different location will speed up or slow down the process....
(and it ranks in the top 5 of my overall favorite demos). My students are blown away after they predict that the ice will melt on the warmer block, yet as soon as the ice cubes are placed on each block, the aluminum block melts the ice cube immediately while the ice cube on the ...
a) Sublimation of dry ice into CO2 gas b) Cs met Does the entropy of the system increase or decrease for each of the following? Explain. a. The evaporation of alcohol. b. The freezing of water. c. Dissolving NaCl in water. Is melting of ice a physical or ...
liquids and liquids into gases.on the other hand,gases can often be turned into liquids and liquids into solids if they are made cold enough.this change of state is a physical change.but if a piece of wood is heated to a high temperautre,it begins to burn,that is a chemical change.by...
The aluminum nanoparticles were obtained from Technanogy (Irvine, CA), and the physical properties of these nanoparticles are listed in Table 1. The sample with an average size of 12.5 nm radius has a broad size distribution with a standard deviation of 10.5 nm. The other four samples have ...
Thermoplastic materials are generally a plastic polymer. They can be cooled and heated many times without any change in physical or chemical...Become a member and unlock all Study Answers Start today. Try it now Create an account Ask a question Our experts can ...
Why do chemical derivatives typically form crystalline solids? Why is melting a physical change? Why is ice the solid form of water? Why is metallic bonding important? List three possible reasons why the melting range of a sample may be broader than desired. What determines the melting point...
During the whole RH refining process, chemical compositions of the molten steel change with the time and position. The sampling position may affect the final result and the mixing time is related to the sampling position. Usually, we prefer to take samples at the position with a short mixing ...