有咩實驗about空氣?急~20點

http://www.youtube.com/watch?v=0Yq3ecszqko

http://www.youtube.com/watch?v=7N-HRkTlR2g

用氣球做實驗,,因你將空氣吹入左個氣球度,佢就會膨漲,,但當你將空氣放出嚟,,佢就會周圍飛,,因好似係輕氣球載人,,升上天空一樣,,原理係氣球裡面有空氣有關,,所以你可以試下用膠氣袋做實驗都得既....

U can test something that about nitrogen,oxygen,carbon dioxide......test for photosynthesis or a glowing splint can or not relight.hope can help you^^