Question

(1) write the quantum numbers for 3d1?

(2) all the elements are not photo electric. Why ?

(3) give equation for photo electric effect and explain the terms?

Answer 1

(1)
n= 3
l= 2
m can have the following values -2, -1, 0, 1, 2
s can have the value +1/2 or -1/2.
As this is the first electron in d orbital so s is +1/2

(2)
The photoelectric effect is the emission of electrons by substances, especially metals, when light falls on their surfaces .
If you illuminate a metallic surface with
electromagnetic radiation that is above a threshold frequency (which is unique to the type of surface and material), the photons are absorbed and electrons are emitted from the surface . No electrons are emitted for radiation with a frequency below that of the threshold, as the electrons are unable to gain sufficient energy to overcome the electrostatic barrier of the work function of the metal.
Non metals are not likely to exhibit any photoelectric effect, because only metals have 'spare' electrons available in their outer shells. It is those 'spare' electrons which are able to be dislodged by the occasional passing photon provided that the photon has sufficient energy. The energy of the photon is determined by the frequency of the radiation - and that also determines the colour if it is visible light - blue having more energy than red. Given all that, some non metals - mostly in the metalloid group - can exhibit weak photoelectric effects if the energy of the impeding photons is high enough - X-rays and so on. Covalent compounds- such as water - are MUCH less likely to show any photoelectric effect, because the electrons are all neatly paired off and bound up in shared electron shells and so on. Not much chance of knocking an electron out of there..

(3)



 

Answer 2

3. Kmax = e V0 = hν − W = h (ν − ν0),