上课铃响过,杜老师神秘地说:“今天,我们来做一个实验,名字叫做‘白糖加热后的变化’。”老师为我们准备了勺子、白糖、酒精灯、火柴。同学们跃跃欲试。实验开始了,我打开酒精灯,划了根火柴把它点燃,把勺子放在上面,开始加热,过了一会儿,伴随着一股清香,勺子底部的糖开始融化成半透明的偏黄色的糖水。渐渐地,勺子里的糖全部成了糖水,然后半透明的糖水颜色慢慢变得深了起来,并且开始冒泡了,一个个指甲大的泡泡泛起来,忽然,勺子里竟然冒起火来。透过火光,我看见糖水不再透明了,变成了紫色,再是深紫色,最 The bell rang, Du teacher mysteriously said: “Today, we have to do an experiment, called the ’sugar after heating changes.’ ” The teacher prepared for us spoon, sugar, alcohol lamp, matches. Students are eager. The experiment started. I turned on the alcohol lamp, drew the match, lighted it, put the spoon on it and started to heat. After a while, accompanied by a scent, the sugar at the bottom of the spoon began to melt into translucent yellowish syrup . Gradually, all the sugar in the spoon became syrup, and then the translucent sugar color became darker and began to bubble up, and large nubbles bubbled up. Suddenly, the spoon burst into fire . Through the flames, I saw the syrup is no longer transparent, into a purple, then dark purple, most