chem: Mg 的flame test

乂...#興乂

Na 嘅 flame test 出 yellow
Ca 嘅flame test 出 brick red
Mg 嘅flame test 出 shiney white
但mg 的 e- 照常理會emit radiation in form of light(discrete line) and back to ground state after excitation，出黎嘅colour 應該係某一色(e.g. calcium出brick red)，唔應該會係白光。假如係白光，咪即係continous spectrum，即係mg嘅 e-可以去哂所有energy level? 又好似冇可能=.=


一條extra的問題:假如flame test 做得耐，例如係咁燒舊 sodium，會唔會愈燒colour愈唔明顯。假如係，係咪因Na-->NaO 每粒sodium少左兩粒electron to promote，所以少左兩粒electron reemit energy~?

Hinton

你第一個問題我未必答到你
因為白光個spectrum係咪超多/continous spectrum
我都唔係好清楚

但第二個問題其實好簡單
你諗返CE
有sodium ions既compund
係flame test 都會出yellow flame

咁Mg 同 MgO 原理一樣姐

paladin

white flash of Mg METAL is due to white hot;
note that it is Mg metal, not compounds, Mg compounds give no visible change in flame color;

and no matter you burn sodium metal or sodium compounds, sodium particles are atomized before excitation, so comsumption of sodium metal to compound will not reduce the phenomenon, the same.

tomy175

做到flame test既係cation而唔係個element 本身
而Mg 燒有佢有flash係因為佢同air react中放光
Mg ion 做flame test係no visible colour