Chem 十分 thx

2007-01-28 7:24 pm

請各位用簡單的文字解述 thx
1. 有沒有物質是沒有mass 的, 如果真的有物質沒有mass, 它算是matter 嗎?
2. Difference between transpiration and evaporation?
3. Difference between gas and vapour?
4. 經常出現excess xx,那麼excee 定義是什麼?

回答 (1)

[匿名]

2007-01-28 8:03 pm

✔ 最佳答案

2. this is a bio question?
transpiration occurs in plants. It is the upward force exerted on the water column in the xylem vessel due to evaporation of water on the leave surface
evaporation: occurs on liquid surface
4. excess: for example, in neutralization, 10cm3 1M NaOH requires 10cm3 1M HCl, if you add 12cm3 HCl( this is more than enough, so it is in excess), you can ensure complete neutralization

Q 1& 2 is something related to definitions: please refers to http://www.wikipedia.org/ for an accurate and full explanation. Just search the words such as 'matter' at the bottom of the page

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