Hey! Do you like science? I like science because it is so i___1___. Here is another experiment. F__2___, you need to put the candle in the candle holder. Then you put the candle holder in a dish and f__3___ the dish with half full of water. L__4__ the candle and let it burn for two or three m__5___. Finally, carefully you put a jar o__6___ the candle. Now watch..
As the candle burns , the water r__7__. When the candle stops b__8____, the water fills about one f___9___ of the jar. Why? Because when the candle burns , it uses u__10____ oxygen, and there is one fifth of oxygen in the air.
1. Interesting(很有趣)
2. First(首先)
3. fill(fill …with…:固定搭配,填满)
4. Light(点上)
5. minutes(分,时间单位)
6. over(盖住)
7. rises(升高)
8. burning(停止燃烧)
9. fifth(1/5)
10. 这个有点问题,楼主确定是u开始么?
会吸水的杯子
思考:用玻璃杯罩住燃烧中的蜡烛,烛火熄灭后,杯子内有什么变化呢?
材料:玻璃杯(比蜡烛高)1个、蜡烛1支、平底盘子1个、打火机1个、水若干
操作:
1. 点燃蜡烛,在盘子中央滴几滴蜡油,以便固定蜡烛。
2. 在盘子中注入约1厘米高的水。
3. 用玻璃杯倒扣在蜡烛上
4. 观察蜡烛燃烧情形以及盘子里水位的变化
讲解:
1. 玻璃杯里的空气(氧气)被消耗光后,烛火就熄灭了。
2. 烛火熄灭后,杯子里的水位会渐渐上升。
答案补充 10.use up
用完,耗尽
杯壁上有小液珠,即水。杯底有黑色物质生成,即炭黑。还会有白烟在杯里,即石蜡小颗粒,会被水溶解。还有,液面不会上升,因为生成二氧化碳。
蜡烛点燃消耗氧气,氧气消耗完蜡烛熄灭,水面上升