物质通常以固态、液态和气态三种状态存在,它们之间可以相互转化,在转化过程中其物态要发生变化,并伴随着吸热和放热.如果以横坐标表示时间,以纵坐标表示温度,从实验可得出物质温度与时间关系的曲线,从这条曲线上可看出物质的温度是怎样变化的,在变化过程中物质处于什么状态.下 Matter usually solid, liquid and gaseous state exists, they can be transformed into each other, the state of change in the conversion process to be changed, accompanied by endothermic and exothermic .If the time indicated by abscissa, the ordinate Said the temperature from the experiment can be drawn material temperature and time curve, from this curve can be seen on the material temperature is how the change in the process of material in what state.