A question about Chemistry

secret

An electronic structure of an atom should have 18 electrons as the maximum no. in the third shell and 2(4^2)  electrons as the maximum no. in the fourth shell(I hope my concept is right),but why the electrons formed in the 3rd shell again after two electrons are formed in the 4th shell?Why not just leave the 3rd shell and continue in the 4th shell? Please help me~

[ Last edited by secret on 2005-12-31 at 09:45 AM ]

抹茶可樂

呢個問題超出你能理解的範圍

總知記著啦，讀chem還有大把謎團是不解的

oscar

當我讀Atom Electronic Arrangement既時候，我都問過我個呀sir
不過我而家唔係好記得...
大約係話咩第19粒atom放入第4個shell個electrons會stable d...
(應該唔o岩...)

secret

Originally posted by oscar at 2005-12-29 11:29 PM:
當我讀Atom Electronic Arrangement既時候，我都問過我個呀sir
不過我而家唔係好記得...
大約係話咩第19粒atom放入第4個shell個electrons會stable d...
(應該唔o岩...)

那麼為什麼要放完兩粒在4th shell後又要再放電子入3rd shell？

dolphin_ice

Originally posted by secret at 2005-12-29 08:59 PM:
An electronic struture of an atom should have 18 electrons as the maximum no. in the third shell and 2(4^2)  electrons as the maximum no. in the fourth shell(I hope my concept is right),but why the ...

中６問題。
你可以揀唔知。

不過，我可以話畀你知點解，但係，你要轉１轉concept。

Concept： (I'll answer your question later. Read this one first so you can understand more)

The electron arrangements in the atom are not only divided into shells.

Shells can be divided into sub-shells
There are 4 types of sub-shells: s, p, d & f

The first shell has 1 sub-shell: s
an S sub-shell can hold 2 electrons.
So the first shell can hold 2 electrons.

2nd shell has 2 sub-shells: s, p
a P sub-shell can hold 6 electrons.
So the 2nd shell can hold 8 electrons.

D sub-shell can hold 10 electrons.
So 3rd shell can hold 18 eletrons.

明啦，就繼續。

ANSWER:
關鍵在於，eletron排列方式，係由低level ge sub-shell排起，而唔係由shell 排起。
由低能量至高能量排，會係咁：

1s                                           低能量
2s                                             |
2p                                             |
3s                                             V
3p                             
4s
3d                                     高能量

咁，3s & 3p 装到8個electrons。
之後ge electrons 會去4s，可以裝２粒。
之後，會去3d，可以装多10粒。

所以，咪會咁搞笑。

PS: 會考唔需要知呢Ｄ
保証唔洗考。

[ Last edited by 紅唇娃 on 2005-12-30 at 05:13 PM ]

secret

Originally posted by 紅唇娃 at 2005-12-30 05:12 PM:

中６問題。
你可以揀唔知。

不過，我可以話畀你知點解，但係，你要轉１轉concept。

Concept： (I'll answer your question later. Read this one first so you can understand more)

The electron ar ...

Thanks~
那麼4s的maximum capacity是2還是2(4^2)？

dolphin_ice

Originally posted by secret at 2005-12-30 08:16 PM:

Thanks~
那麼4s的maximum capacity是2還是2(4^2)？

4s maximum capacity 是2

但 4 有齊晒 s,p,d,f

中５只需知道到 2, 8, 8, 2 的 Calcium.
Calcium打後ge element唔會教，亦唔洗考。

secret

Originally posted by 紅唇娃 at 2005-12-31 05:06 PM:

4s maximum capacity 是2

但 4 有齊晒 s,p,d,f

中５只需知道到 2, 8, 8, 2 的 Calcium.
Calcium打後ge element唔會教，亦唔洗考。

f是不是擁有最高能量的sub-shell？
另外，Scandium的electron structure是不是2,8,9,2？

dolphin_ice

係。

都係。
排到 2, 8, 18, 2 之後就 2, 8, 18, 3 ...

secret

Originally posted by 紅唇娃 at 2005-12-31 10:11 PM:
係。

都係。
排到 2, 8, 18, 2 之後就 2, 8, 18, 3 ...

明白了
thanks jynx