(a) Explain why(i) metals are good conductors of electricity.(ii) insulators do not conduct electricity.[3] 相关知识点: 试题来源: 解析 (a) mark (i) and (ii) together:mention of free electrons(current is) flow/movement of free electronsinsulators contain no free electrons / metals contain...
Metals are good conductors of heat and electricity because they contain a glut of free electrons. These free electrons are able to move around freely and collide with one another, propagating heat and electricity through the metal. The majority of materials that conduct heat and electricity are m...
材料科学与工程基础10 11思考题
60年代国际经济合作 ___，既有技术层面的原因又有制度层面的原因。
材料科学与工程基础作业讲评-7 第十次作业中文 4-12热处理（退火）的实质是什么？它对材料的拉伸强度、硬度、尺寸稳定性、冲击强度和断裂伸长率有什么影响？结构弛豫，非晶至结晶转变 4-20玻璃的理论强度超过7000MPa。一块平板玻璃在60MPa弯曲张力下破坏。我们假定裂纹尖端为氧离子尺寸（即裂纹尖端...
Why metals react more vigorously in acids than in water? Explain why ionic solids do not conduct electricity in the solid state but are strong conductors in the liquid state and when dissolved in water. Why do some electrochemical cells employ inert electrodes such as platinum?
Explain why it is more difficult to produce drinking water from wastewater than from water in lakes. Why are metals good conductors of electricity? Sulfur deposits are mined by the Frasch process. Explain why f...
All Siltech Silver-Gold alloys (an alloy means a mix of two or more metals) do have positive aging. In other words, electrically, the wires improve over time, even when not playing music. Moreover, distortion reduces over the years, continuously improving sound quality. These special propertie...
While copper and silver are both more efficient electrical conductors than gold, that efficiency degrades as the connections tarnish and corrode. Gold connectors, however, do not tarnish or corrode. This makes gold the preferred choice for plating electrical connectors and in integrated circuits. ...
b. are stable to much higher temperatures. c. have a lower density. d. are better electrical conductors. e. none o Which of the following are properties of metals? More than one answer is correct. (a) good conductor of electricity and heat (b) low density (c) relatively ...