 # How did plank explained the black body radiation?

Based on Max Plank’s postulates of electromagnetic radiation, Plank explained the black body radiations.

✔ Matter can either absorb or release energy only of some characteristic frequencies and not all.

✔ Energy absorption or emission hence cannot be continuous but only discrete.

✔ The energy absorbed or emitted = E = hν: where,

h is a Planks constant= 6.626 ×10-34 Js and ν is the frequency of radiation.

✔ Total energy of the radiation is emitted is an integral multiple of this basic unit. E= nhν

✔ Intensity function; ρ(λ,T)

$$\begin{array}{l}=frac{2h{{c}^{2}}}{{{lambda }^{5}}}times frac{1}{frac{hc}{{{e}^{lambda KT}}}-1}\end{array}$$

When, λ → 0,

$$\begin{array}{l}frac{hc}{{{e}^{lambda KT}}}=frac{hc}{lambda KT}+1\end{array}$$
, so that,

=

$$\begin{array}{l}=,frac{2h{{c}^{2}}}{{{lambda }^{5}}}times frac{lambda KT}{hc},=frac{2cKT}{{{lambda }^{4}}}\end{array}$$
= Reyleigh -Jeans formula

So, Plank’s, relation is valid even at low wavelength and does not predict ‘ultraviolet catastrophe’.

The particle (quantum) model proposed by Max Plank explains black body radiation,. (3) (1)