答:水和大多数其它物质不同:当温度降低时,大多数物质的密度不断地变大,但水的密度却以在4℃时最大,无论温度高于或低于4℃时,它的密度都要比较小一些。一般物质,当温度升高时体积变大密度变小的原因,可以用分子运动学说来解释。就是:因为当温度升高的时候,随着分子热运动的剧烈化,分子间的平均距离变大了。 A: Water differs from most other substances: As the temperature decreases, the density of most substances continues to grow, but the water density is greatest at 4 ° C, regardless of whether it is at or below 4 ° C Density should be smaller. The general substance, the reason why the volume becomes larger as the temperature increases, and the density becomes smaller, can be explained by molecular kinematics. That is: because as the temperature rises, the average distance between molecules becomes larger as the heat of molecules heats up.