学习分子动理论知识时,老师常常做这样一个演示实验: 在一根较长的玻璃管中注入一半水,再缓缓地倒满酒精,用塞子塞住开口端,上下颠倒几次再竖起来,可以看到玻璃管中的液面降下去了.这个实验直观地说明了分子间存在着空隙.一次,在演示这个实验时,一个同学忽然提了这么一个问题:刚才降下去的液面和塞子之间是真空吗? When learning the theory of molecular dynamics, the teacher often performs such a demonstration experiment: Inject half of the water into a long glass tube, then slowly fill it with alcohol, plug the open end with a stopper, and turn it upside down several times. It can be seen that the liquid level in the glass tube has dropped. This experiment shows intuitively that there are gaps between the molecules. Once, in the demonstration of this experiment, a classmate suddenly asked the question: the liquid level that was just dropped and Is the vacuum between the plugs?