The  energy needed to convert helium atom  to He ⁺² is -79eV. The first ionization energy of this atom is about 

1. 65.4eV

2. 51.8eV

3. 24.6eV

4. 27.2eV

A cricket ball of 0.5 kg is moving with a velocity of 100 ms^-1. The wavelength associated with its motion is:

1. 1/100cm

2. 6.6 x 10^-34m

3. 1.32 x 10^-35m

4. 6.6 x 10^-28m

If the velocity of a particle is reduced to 1/3^rd, then percentage increase in its de-broglie wavelength will be:-

1. 100%

2. 200%

3. 50%

4. 33.33%

The maximum wavelength in the Lyman series of He⁺ ion is-

1. 3R

2. 1/3R

3. 1/R

4. 2R

 When an electron jumps from n=5 to n=1 in a hydrogen atom, the number of spectral lines obtained is 

The number of electrons that can be fit into the orbital for which n = 3 and l = 1, is:

1. 2

2. 6

3. 10

4. 14

Magnetic moment of 2.83 BM is given by which of the following ions?

(At no: Ti=22; Cr=24; Mn=25; Ni=28)

1. Ti³⁺                 

2. Ni²⁺

3. Cr³⁺                 

4. Mn²⁺

The correct set of four quantum numbers for the valence electron of rubidium atom (Z =37) is

1. 5, 1, 1, +1/2               

2. 6, 0, 0, +1/2

3. 5, 0, 0, +1/2               

4. 5, 1, 0, +1/2

The orientation of an atomic orbital is governed by:

1. Azimuthal quantum number

2. Spin quantum number

3. Magnetic quantum number

4. Principal quantum number

Orbitals having two spherical nodes are: