Keadaan Jirim Air

Air wujud dalam tiga keadaan iaitu solid, liquid dan gas.

Proses-proses dalam perubahan keadaaan jirim air :

1. Freezing - from liquid to solid

2. Boiling / evaporation - from liquid to gas

(* p/s : there are differences between boiling and evaporation. we shall discuss this in the next subtopic)

3. Melting - from solid to liquid

4. Condensation - from gas to liquid

There are few substances, which can change from solid directly to gas and vice versa (without liquid state) such as :

i) iodine

ii) dry ice (carbon dioxide in solid form)

The process is known as sublimation.

The process which absorbed heat :

- melting

- boiling

- sublimation (solid to gas)

The process which released heat :

- freezing

- condensation

- sublimation (gas to solid)