## anonymous one year ago 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.

1. Abhisar

Hello @boen !

2. Abhisar

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.

3. anonymous

@Abhisar That does make sense.. Thanks

4. Abhisar

You're welcome (-: