Question

write the significance of planck's proposal?

Answer 1

(1).The emitted or absorbed radiation is due to the vibration of charged particles(electrons) in the body
(2).The emitted radiation is not continuous,but it is in the form of smal discrete packets of energy called "Quantum".
(3).The energy associated with each quantum(E) is given by →E = hC/lambda.

Answer 2

$\large\tt\red{Answer\::}$

The significance of Planck's proposal is that, electromagnetic energy can be gained or lost in discrete values and not in a continuous manner.