Question

Light from Balmer series of hydrogen is able to eject photoelectrons from a metal. What can be the maximum work function of the metal?

Answer 1

Answer:

w° = hf - 1/2 mv²

Explanation:

we know that from Einstein photoelectric equation;

hf - w° = 1/2 mv²

where w° = work function

hf = energy of photon

1/2 mv² = total kinetic energy from ejection of electron.

then,

w° = hf - 1/2 mv²

Answer 2

The maximum work function of the metal is 3.4 eV When light from Balmer series of hydrogen is able to eject photo electrons from it.

Explanation:

Assume that the metal’s maximum work function be denoted as W.

In the Balmer Series (E), the liberated energy is shown as

$E = 13.6 \times ( \frac{1}{n_1^{2}} - \frac{1}{n_2^{2}} )$

Maximum energy of Balmer series is taken for maximum work function

Now, $n_1$ = 2  and $n_2 = \infty$

Therefore, maximum energy $E = 13.6 (\frac{1}{2^{2}} )$

maximum energy $E = 13.6 \times ( \frac{1}{4} )$

maximum energy E= 3.4 eV

Here, Maximum energy is considered as the  Maximum work function of the metal,

Maximum  energy = maximum work function

                           E = W

So, the maximum work function of the  metal is 3.4 eV