有關科學(水既實驗)

首先用中文簡介一下...
我地知道，o係燃燒作用(for 蠟燭)入面...
蠟(燃料) & 氧氣係必要o既... 過程會產生二氧化碳同水...
成個過程入面，氧氣同二氧化碳係唯一o既氣體...
如果經過深入o既計算... 我地就會計倒，二氧化碳(生成物)比氧氣(反應物)o既總佔有量少。
而且，因為係完全蓋住，冇其它氣體o既補充，所以就唯有用水做"補充"...
物理o的咁講... 因為個氣壓下降.. 而個水壓就因此高左，所以就"吸"左入去...
以下係英文o既詳盡解釋連計算：
[Suppose we cover the candle with a glass cup]
Combustion requires oxygen gas (氧氣) and fuel (燃料),
and produces water and carbon dioxide (二氧化碳),
which the mass of carbon dioxide is usually smaller than that of oxygen.
Therefore, the "size" of the gas decreased. Hence, the air pressure (氣壓) inside the glass cup is lowered.
It explains why it "absorbs" water.
可能勁d o既人會反駁話：
「O2 "變做" CO2... 多左個C (Carbon atom)... 照計應該個空氣佔有量會更大，所以d水應該會"走出去"...」
以下一個例子就可以解釋：
Use paraffin wax (石蠟) as an example of the candle fuel, which the chemical formula (化學公式) is C25H52.
The word equation for the combustion reaction is: (△ stands for heating)
Paraffin wax + Oxygen gas -----△----> Carbon dioxide + Water
So... the chemical equation for the combustion reaction is:
C25H52 + O2 -----△----> CO2 + H2O <<<<< Not balanced yet~!!
After balancing:
C25H52 (s) + 38O2 (g) ----△----> 25CO2 (g) + 26H2O (l)
O2 and CO2 is the only gas in this reaction, so we can compare the "size" of them.
The Mole Ratio of O2 : CO2 = 38 : 25 (Mole ratio 簡單o的可以話係兩個物質總共o既atom數 [原子數] o既比例)
So... we can say the gas size decrease by (38-28)/38 = 26.3%
換句話講，燃燒依種蠟，如果有100cc 氧氣，就會吸26.3ml 水 (記住係氧氣，而唔係空氣，因為個化學作用反應物係個氧氣 + 蠟，而並非包括其它氣體)
(plz also note that 26.3% this number is only for a complete combustion.... usually the number will be smaller, as oxygen is usually not all used up.... before the fire is "off"
but of coz it will not be negative = =||...)
Because there is no supplement (補充) of other gases [因為佢完全蓋住].
Therefore, it explains why water is "absorbed".

2008年7月21日 ~by博文
今晚, 爸爸陪我地睇一本有關科學實驗o既書, 裏面提到好多簡單o既科學實驗~
當中, 有一個就話可以用玻璃杯盛載住唔同容量o既水, 敲落去就可以發出高低唔同o既聲音~
於是我地就叫爸爸幫手, 然後就開始我地呢個科學實驗~
圖片參考：http://f20.yahoofs.com/hkblog/cKtVkOSBFQX91EmlU7z1OOdzThQ-_58/blog/ap_20080722104858819.jpg.jpg?ib_____D97C9cnr7

using a glass bottle to cover the candle
when the oxygen in the glass bottle is burnt,
the pressure inside the glasss bottle decrease
so the water will be sucked up