為什麼水的沸度是100度？

In the old day, people do use Fahrenheit (F) as unit of temperature, later they need to use a new scale, so they use the freezing point and boiling point of water as the reference, that is 0 and 100 degree Celsius (C).

Please remind that the freezing point and boiling point of water is pressure dependent, that is for a higher pressure, the freezing point and boiling point of water will be higher, and vice the verse.

The new standard is using the triple point of the water as the reference, for more information, go to search in web or wiki for the phase diagram of water. The triple point is the equilibrium of 3 phases of water, the gases (vapour), liquid (water) and solid (ice).

物理量只係人定出嚟

100度是水的沸點
因為攝氏溫標把水的沸點定為100度

水係冇100度,因為水含有其它物質, 所以水只是接近100度,但係點解D人話係100度,是因為貪放便/記錯了是[水蒸氣(它是100度以上) ]