Chemistry : Extraction - Physical Method

Physical Extraction of Metal 係 用嚟 Extract Gold, Platium 這些 Reaction Rate 較細 而 好 stable ge compound. 係過程入面, 通常只會involve Physical Method (即係 Minning, (Only change of size, shape etc. but no energy absorbed 同 given out).
其實最簡單ge Physical Method 就係將糖熔落去 water 度..佢只不過係一個mixture而唔係一個compound form.只要係過程之間沒有Energy change就係Physical Method.
其實Physical Method 同 Chemical Method 都冇優點同缺點. 因為各種Metal ge Extraction Method都係唔同.
For example:
Reaction rate 高 (e.g. Aluminium) use Chemical Method (Electroylsis of Molten Ore)
Reaction rate 中 (e.g. Iron) use Carbon Reduction (Chemical Method)
Reaction rate 低 (e.g. Gold) use Simple Minning (Physical Method)..

dissolving sugar into the water is physical change instead of physical method.
i think the biggest disadventage of chemical method to seperate the metal from the ores is the cost is too high when it have to distract some really reactive metal cox it requires a large amount of electricity .