解析 C。解析:化学变化是产生新物质的变化。A 改变物质颜色可能是物理变化,如颜料混合。B 冰融化是物理变化,状态改变。C 燃烧木材产生新物质,是化学变化。D 压扁易拉罐是物理变化,形状改变。本题考查对化学变化概念的理解,涉及词汇有 chemical change(化学变化)、substance(物质)等。
百度试题 结果1 题目Chemical changes often involve a change in ___. A. color B. size C. shape D. weight 相关知识点: 试题来源: 解析 A。化学变化通常会涉及颜色的变化,而大小、形状和重量一般在物理变化中可能改变更多。反馈 收藏
1. In a physical change__ is formed. A.a new substance B.nothing new C.a piece of paper D.a piece of iron (4). 4. We can separate a chemical change from a physical one by__ . A.the change of shape B.the change of color C.newly-produced smoke D.newly-formed subatances 相...
Chemical reactions often involve a change in ___. A. color B. shape C. size D. weight 相关知识点: 试题来源: 解析 A。化学反应经常涉及颜色的变化。形状、大小和重量的变化不一定是化学反应的典型特征,而颜色变化在很多化学反应中较为常见,所以选 A。反馈 收藏 ...
The color change from colorless to pink in a chemical reaction may indicate the presence of _. A. acid B. base C. salt D. water 相关知识点: 试题来源: 解析 B。化学反应中从无色变为粉红色可能表明有碱的存在。A 选项酸一般不会有这种颜色变化;C 选项盐通常也不会有这样的变化;D 选项水是...
Color change of chemical indicators. II. Acid-base indicators.Kotrly, StanislavVytras, KarelOharek, JiriVondruskova, Eva
FTIR and color change of the modified wood as a result of artificial light irradiation The effect of UV鈥搗isible light irradiation on the changes in color and chemical composition of the surfaces of Abies alba L. (fir, a softwood), non-modif... R Dan,CA Teaca,R Bodirlau,... - ...
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 ...
Certain acid-sensitive pigments may be subject to chemical change in oxidizing systems, which cure by the introduction of oxygen. With many such paints, the observed change is a deterioration in color. The postaddition of thixotropes during the pigment dispersion phase can reduce flow, and in ...
To request such a change, the Editor must receive the following from the corresponding author: (a) the reason for the change in author list and (b) written confirmation (e-mail, letter) from all authors that they agree with the addition, removal or rearrangement. In the case of addition ...