Question

The longest wavelength that can eject photoelectrons from platinum is 1950 angstrom. Calculate its work function

Answer 1

if you go to approx answere then it will be about of 6.25eV

Answer 2

Answer:

The expression of wavenumber(ṽ) is given by,Wave number (ṽ) is inversely proportional to wavelength of transition. Hence, for the longest wavelength transition, ṽ has to be the smallest.According to Balmer formula

ṽ=1/λ = RH[1/n12-1/n22]

For the Balmer series, ni = 2.

Thus, the expression of wavenumber(ṽ) is given by,

Wave number (ṽ) is inversely proportional to wavelength of transition. Hence, for the longest wavelength transition, ṽ has to be the smallest.

For ṽ to be minimum, nf should be minimum. For the Balmer series, a transition from ni = 2 to nf = 3 is allowed. Hence, taking nf = 3,we get:

ṽ= 1.5236 × 106 m–1

hope it helps D:

Explanation: