Atoms

The de-Broglie wavelength of an electron in the first Bohr orbit is

• equal to half the circumference of the first orbit

• equal to one fourth the circumference of the first orbit

• equal to the circumference of the first orbit

• equal to twice the circumference of the first orbit

Whenever a hydrogen atom emits a photon in the Balmer series, it

• may emit another photon in the Paschen series

• need not emit any more photon

• may emit another photon in the Balmer series

• must emit another photon in the Lyman series

In the Bohr model of the hydrogen atom, let R, V and E represent the radius of the orbit, the speed of electron and the total energy of the electron respectively. Which of the following quantity is proportional to the quantum number n ?

• $\frac{\mathrm{E}}{\mathrm{V}}$

• $\frac{\mathrm{R}}{\mathrm{E}}$

• VR

• RE