1

### IIT-JEE 1996

Subjective
Consider the hydrogen atom to be a proton embedded in a cavity of radius a0 (Bohr radius) whose charge is neutralised by the addition of an electron to the cavity in vacuum, infinitely slowly. Estimate the average total energy of an electron in it's ground state in a hydrogen atom as the work done in the above neutralisation process. Also, if the magnitude of the average kinetic energy is half the magnitude of the average potential energy, find the average potential energy.

$- {{{e^2}} \over {4\pi \varepsilon {}_0.{a_0}}},{{ - {e^2}} \over {8\pi \varepsilon {}_0.{a_0}}}$
2

### IIT-JEE 1996

Subjective
Calculate the wave number for the shortest wavelength transition in the Balmer series of atomic hydrogen.

27419.25 cm-1
3

### IIT-JEE 1995

Subjective
Iodine molecule dissociates into atoms after absorbing light of 4500 Å. If one quantum of radiation is absorbed by each molecule, calculate the kinetic energy of iodine atoms. (Bond energy of I2 = 240 kJ mol-1)

2.165 $\times$ 10-20
4

### IIT-JEE 1993

Subjective
What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4 to n = 2 of He+ spectrum?

n = 2 to n = 1