# Please explain plank's quantum theory.

### Asked by Benjamin | 13th Oct, 2015, 05:23: PM

###
To explain the phenomena of ‘Black body radiation’ and ‘Photoelectric effect’, Max Plank in 1900, put forward a theory which is known after his name as Plank’s quantum theory.

The main points of this theory are as follows:

(i) The radiant energy is emitted or absorbed not continuously but discontinuously in the form of small discrete packets of energy. Each such packet of energy is called a ‘quantum’. In case of light, the quantum of energy is called a ‘photon’.

(ii) The energy of each quantum is directly proportional to the frequency of the radiation, that is

E ∝ ν or E = hν

where is h is proportionality constant, called Plank’s constant. Its value is approximately equal to 6.626×10^{-27} erg sec or 6.626×10^{-34} joule sec.

(iii) The total amount of energy emitted or absorbed by a body will be some whole number quanta.

Hence, E = nhν where n is any integer.

To explain the phenomena of ‘Black body radiation’ and ‘Photoelectric effect’, Max Plank in 1900, put forward a theory which is known after his name as Plank’s quantum theory.

The main points of this theory are as follows:

(i) The radiant energy is emitted or absorbed not continuously but discontinuously in the form of small discrete packets of energy. Each such packet of energy is called a ‘quantum’. In case of light, the quantum of energy is called a ‘photon’.

(ii) The energy of each quantum is directly proportional to the frequency of the radiation, that is

E ∝ ν or E = hν

where is h is proportionality constant, called Plank’s constant. Its value is approximately equal to 6.626×10^{-27} erg sec or 6.626×10^{-34} joule sec.

(iii) The total amount of energy emitted or absorbed by a body will be some whole number quanta.

Hence, E = nhν where n is any integer.

### Answered by Prachi Sawant | 14th Oct, 2015, 10:36: AM

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