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

Correct set of four quantum numbers for the outermost electron of rubidium (Z=37) is:

1. 5, 0, 0, 1/2

2. 5, 1, 0, 1/2

3. 5, 1, 1, 1/2

4. 6, 0, 0, 1/2

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

(4) Electron 4            3             1             0           -1/2

The correct order of decreasing energy of these electrons is - 

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

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

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

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

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 

1. 4

2. 5

3. 6

4. 7

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.

1. 1.25 Å

2. 0.75 Å

3. 0.25 Å

4. 1.00 Å

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

1. 1/4

2. 4

3. 1/2

4. 2

The ion that is isoelectronic with CO is-

1. CN^-

2. O₂⁺

3. O₂^-

4. N₂⁺

If frequency of the X-rays produced using an element as anti-cathode is found to be 2500 sec^-1, the atomic number of used element is (a, b= 1)

1. 51

2. 49

3. 56

4. 72

When the atoms of gold sheet are bombarded with a beam of $\alpha$ -particles, only a few a-particles get deflected where as most of them go straight undeflected. This is because:

The number of electrons in the valence shell of calcium is 

1. 6

2. 8

3. 2

4. 4