一、激情导入,引发兴趣师:我先给同学们做一个小实验。请同学们看投影。我把一个盛水的烧杯放在投影仪上,向水中投入几粒高锰酸钾颗粒,谁愿意说说你观察到的现象?生1:膨涨的高锰酸钾颗粒逐渐扩散,化成极小极小的微粒像一股红烟似的飘散到水中,好美呀!生2:清水变成红色的了。高 First, the introduction of passion, sparking interest division: I first give the students a small experiment. Please classmates to see the projection. I put a water-filled beaker on the projector, into the water a few grains of potassium permanganate, who are willing to talk about your observed phenomenon Health 1: swelling of potassium permanganate particles gradually spread into a polar Small tiny particles like a fiery red smoke into the water, so beautiful! Health 2: water into a red. high