将一铁块放在炉子里加热 ,则它的质量、体积、密度如何变化 ?正确答案是质量不变 ,体积变大 ,密度变小。可是有不少同学认为是密度不变。他们说 ,密度是物质的一种特性 ,既然是特性 ,所以无论在什么情况下都是不会改变的。究竟物质的密度是否会变化呢 ?关键是要了解和掌握密度 When a piece of iron is heated in a furnace, how does its mass, volume, and density change? The correct answer is that the mass is constant, the volume becomes larger, and the density becomes smaller. However, many students believe that the density is the same. They said that density is a characteristic of matter. Since it is a characteristic, it will not change under any circumstances. Does the density of the material change? The key is to understand and master the density.