作者puppybaby (小狗兒)
看板Chemistry
標題[學科] 幾題問題
時間Mon May 16 20:49:36 2011
碰到了一些問題想破頭,請大家幫忙
1. Which of the following atoms is likely to be radio-active?
A) 13 B) 23 C)27 D) 28 E) 56
C Na Al P Fe
答案是D) 解答寫質子與中子數為奇數較不穩定
請問這個意思是??
2. The mole percent of helium is 0.000524. What is the concentration of
helium in parts per million (ppm)?
A) 5.24x10^-2 B) 5.24 C) 5.24x10^-4
D) 5.24x10^-5 E)5.24x10^-3
1ppm
答案是B) 解答寫 5.24x10^-4x ______ =5.24x10^-2 ppm =5.24%ppm
10^-6
請問它為甚麼要這樣算? 整個看不懂QQ 有其他比較清晰的解法嗎??
3. Which one of the following statements is not true？
A) If one electron is removed from the highest occupied orbital of N2，the
bond order decreases.
B) The ionization of molecular hydrogen (H2) is higher than that
of atomic hydrogen(H).
C) The ionization of molecular oxygen (O2) is lower than that of
atomic oxygen(O).
答案是A)
可是A應該是對的吧 那B和C各是甚麼意思呢?
希望大家幫我解答一下
謝謝><
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