The number of d- electrons retained in Fe^{2+ :}

Which of the following sets of quantum numbers is not possible?

Which of the following sets of quantum numbers represent an impossible arrangement - 

       n   l    m     s

How many unpaired electrons are present in Ni²⁺ cation (atomic number = 28)

Number of unpaired electrons in 1s² 2s² 2p³ is -

The quantum numbers of four electrons are given below.

                                  n            $\mathcal{l}$           m          s 

(1) Electron 1             3            0             0           -1/2

(2) Electron 2             4            0             0           1/2

(3) Electron 3            3             2             0           1/2

The correct order of decreasing energy of these electrons is - 

1. Electron 3 > Electron 1 > Electron 4> Electron 2

Which type of radiation is not emitted by the electronic structure of atoms:

An absorption line of the lowest frequency in the transition of hydrogen spectra is

If uncertainty in the position of an electron is zero the uncertainty in its momentum will be

The maximum number of atomic orbitals associated with a principal quantum number 5 is-

The de Broglie wavelength of electron of He⁺ ion is 3.329Å. If the photon emitted upon de-excitation of this He⁺ ion is made to hit H atom in its ground state so as to liberate electron from it, what will be the de Broglie's wavelength of photoelectron ?

Velocity of helium atom at 300 K is 2.40 x 10² meter per sec. What is its wavelength? (mass number of helium is 4) -

If the Planck’s constant h=6.6 x 10^-34 Js, the de-Broglie wavelength of a particle having the momentum of 3.3 x 10^-24 kg m s^-1 will be

Which of the following statements is not true with respect to photoelectric effect -

The first line in the Lyman series in the spectrum of hydrogen atom occurs at a wavelength of 1215 Å and the limit for Balmer series is 3645 Å. Calculate the wavelength corresponding to series limit of Lyman series.

The correct order of increasing energy of atomic orbital is

In Rutherford's alpha scattering experiment using gold foil, the kinetic energy of the alpha particle was 1.2 x 10^-12J. For a head on collision, using the formula K.E. = $\frac{1}{4{\mathrm{\pi \epsilon }}_0}$x 2Ze²/r₀ , what may be the magnitude of r₀ [ The nuclear radius of gold, Z=79; $\frac{1}{4{\mathrm{\pi \epsilon }}_0}$= 9 x 10⁹ new-ton/meter² coulomb^-2, e= 1.6x10^-19 coulomb]

The quantum number of the most energetic electron in an Ne atom in the first excited state is

The frequency of line spectrum of sodium is 5.09 x 10¹⁴ sec^-1. Its wavelength (in nm) will be -[C= 3x10⁸m/sec]

The total number of neutrons in dipositive zinc ions with mass number 70 is -

With a certain exciting radiation of a particular frequency, to which hydrogen atoms are exposed, the maximum number of spectral lines obtainable in the emission is 15. The uppermost energy level to which the electron is excited is 

Consider an electron which is brought close to the nucleus of the atom from an infinite distance, the energy of the electron-nucleus system:

When accelerated electrons are direct against an anticathode in an X-ray tube, the radiation obtained has a continuous spectrum with a wavelength minimum,

${\lambda }_{min} =\frac{ (1.24 x {10}^{-6})}{V}$) m, where V is the voltage used for accelerating the electrons.

Calculate $\lambda$_min for V= 5 x 10⁴ volts.

Calculate the de Broglie wavelength of an $\alpha$-particle emitted from radium having an energy of 4.8 MeV.

(Mass of $\alpha$-particle=6.6 x 10^-24 g; h=Planck's constant = 6.626 x 10^-27 erg sec)

An atom forms an ion by losing three electrons. The ion has an electronic configuration [Ar]3d⁶. The symbol of the ion is :

The frequency ratio between violet (400nm) and red (750nm) radiations in the visible spectrum, is-

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

Using arbitrary energy units we can calculate that 864 arbitrary units (a.u.) are required to transfer an electron in hydrogen atom from the most stable Bohr's orbit to the largest distance from the nucleus 

n = $\infty$   E= 0

n = 1 ;   E= -864 Arbitrary units

The energy required to transfer the electron from third Bohr's orbit to the orbit n = $\infty$will be-

The sub-shell that comes after f-sub-sell is called g-subshell. The number of g-sub orbitals in g-sub-shell and the total number of orbitals in the principal orbital respectively are-

The wavelengths of two photons are 2000 Å and 4000 Å respectively. What is the ratio of their energies?