F4 CHEM water同grahite神秘之謎..

1.
係H2O, O既電負性比H強(i.e.O比H更能吸多D電子)
所以H2O其實係有ionic character
但係又有covalent character
所以可以電解成H+ 同OH-
其實即使係NaCl都有D covalent character

2.
covalent bond唔係share完之後每粒atom都變成最外層電子有8粒嗎? 唔係
要舉例既話係有BCl5 (B有10粒)

唔講題外話，graphite既delocalized e- 係來自overlap of unhybridize p shell e-(AL會講，DSE好似唔使學)

2009-11-09 19:45:06 補充：
上面有D問題
其實graphite既delocalized e-係因為佢唔夠能量做4個bond(diamond)
所有一個電子要同其他C既電子做一舊雲(pi bond)
咁先係有自由電子

上面果幾位講得都好深+_+
對於F.4黎講太難啦.
我今年都係F.4,所以下面就係我最近上堂學既.

其實GRAPHITE佢之所以可以通電,完全係因為佢得7粒電子,就正正因為佢既電子要不斷的走動以達致有OCTET STRUCTURE,所以不間斷甘不斷走不斷走,一時有一D有8粒電子,一時果度又得番6粒甘.
我教CHEM既老師就係話你搶我我搶你甘不斷走,所以形成自由電子.

Hope I can help you !



1. H2O is a molecular compound , the main reason is this compound is

combined from 2 hydrogen atom (H2) and 1 oxyen atom (O) .

As everyone know , hydrogen and oxyen both are non-metal .

So that , this compound is not ionic but molecular .

呢個係中六chem既問題黎架喎,讀到中六你就會明!