密度是一个十分重要的概念,且在生产和生活中有着较广泛的应用.学习时须在概念的理解和应用两个方面下功夫,才能达到教学大纲要求的层次,能较灵活地运用.下面针对这两个方面进行阐述和拓展.一、对概念的理解对密度概念的理解应注意以下几点:1密度是物质单位体积的质量,它表示出 Density is a very important concept, and has a wide range of applications in production and living.Study in the concept of understanding and application must work hard in order to achieve the level of teaching syllabus requirements, can be more flexible to use. For these two aspects to elaborate and expand.First, the concept of understanding The concept of density should pay attention to the following points: 1 density is the mass of the material unit volume, it shows