Question

In my book says :
"Energy is in fact "quantized" and can only be transferred in discrete units of size hv. Each of the small "packets" of energy is called a quantum. A system can transfer energy only in whole quanta."
I don't really understand what is means. Can you explain? Thank you.

Answer 1

Hello @boen !

Answer 2

To understand the concept let's take an analogy. Suppose there is a store room full with 1 kg flour packs. Now if someone asks you to transfer 4kg of flour out of the room then the only way you can do that is by picking 4 packs of flour and keeping it outside the room. Here, we see that mass of flour is \(\sf quantized\) and can be transferred only in discrete units that is 1 kg packs.

Similarly, energy is quatized for example light energy. Energy in the form of light can only be transferred in the form of discrete packets or units called as \(\sf Photons \) (special name for quanta of light energy). You can not transfer energy in any unit smaller than the photon and the amount of energy transferred will always be a whole number multiple of photo i.e 5 photons, 6 photons etc. It can't be 4.5 photon, 6.7 photon etc.The amount of energy in one photon can be given by the equation

\(\boxed{ \sf E=h\nu}\), where,
E= energy
h=plank's constant
\(\nu\) = frequency of light.

Answer 3

@Abhisar That does make sense.. Thanks

Answer 4

You're welcome (-: