有冇人可以話我知咩係physical properties同chemical properties???

Chemical properties refer the chemical reaction the substance will have under certain conditions. For example, when Iron reacts with oxygen, it will form rust (Fe2O3<---the chemical formula of rust) So this is the chemical reaction, right? Then we can say it as the chemical property of Iron.

Physical properties refer to properties than can determined without changing the chemical composition of the substance, that is, not about chemical reaction.

Physical poperties include state, colour, hardness, density, electrical conductivityodour, tase, heat conductivity,etc.

So take an example of water,

State: Liquid at room condition
Colour: colourless
electrical conductivity: poor conductor if it's pure

another example, oxygen state: gas at room condition
colour: colourless

Since nitrogen's physical properties are quite the same as oxygen, so we cna't distinguish them just comparing their physical properties, then we have to compare their chemical properties. Oxygen reacts with hydrogen to form water, but nitrogen doesn't. There, you can distinguish them.

英文先~

2007-10-03 20:18:30 補充：
中文大致上係咁：一樣野經過左reaction會變左第二d野or出左d新既compound出黎呢d野都有Chemical properties而好似水咁佢無論係不同的溫度變黎變去都係本身自己係水唔會有新既compund出現呢個都叫有Physical properties 總之你記住有新既compund出黎就叫Chemical properties無既係Physical properties