Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate threshold frequency (ν0 ) and work function (W0 ) of the metal.

Asked by Pragya Singh | 1 year ago |  111

##### Solution :-

Threshold wavelength of the radiation

$$(\lambda _{0}= 6800 Å$$

$$6800\times 10^{-10}\, m)$$

Threshold frequency of the metal

$$\nu _{0} =\dfrac{c}{\lambda _{0}}$$

$$=\dfrac{3\times 10^{8}ms^{-1}}{6.8\times 10^{-7}m}$$

$$=4.41\times 10^{14}\, s^{-1}$$

Therefore, threshold frequency $$\nu _{0}$$ of the metal

$$=h\nu _{0}\\ \\$$

$$=(6.626\times 10^{-34}Js)(4.41\times 10^{14}s^{-1})\\ \\$$

$$=2.922\times 10^{-19}\, J$$

Answered by Pragya Singh | 1 year ago

### Related Questions

#### How many sub-shells are associated with n = 4?

Answer the following questions:-

(a) How many sub-shells are associated with n = 4?

(b) How many electrons will be present in the sub-shells having ms value of $$- \dfrac{1}{2}$$ for n = 4?

#### Indicate the number of unpaired electrons in:

Indicate the number of unpaired electrons in:

(a) P

(b) Si

(c) Cr

(d) Fe

(e) Kr

#### The unpaired electrons in Al and Si are present in 3p orbital.

The unpaired electrons in Al and Si are present in 3p orbital. Which electrons will experience more effective nuclear charge from the nucleus?

#### Among the following pairs of orbitals which orbital will experience the larger effective nuclear charge?

Among the following pairs of orbitals which orbital will experience the larger effective nuclear charge?

(i) 2s and 3s,

(ii) 4d and 4f,

(iii) 3d and 3p