Beryllium's fourth electron will have the four quantum numbers :

                         n               $\mathcal{l}$               m             s

1.                    1               0                0             1/2

2.                    1               1                1             1/2

3.                    2               0                0             -1/2

4.                    2               1                 0             +1/2

Mass of neutron is ........................times the mass of an electron-

1. 1840

2. 1480

3. 2000

4. None of the above

If the size of the first orbit of the hydrogen atom is 5.29 nm, the size of the second orbit of He⁺ is

1. 2.65 nm

2. 21.16 nm

3. 10.58 nm

4. 5.29 nm

Which one of the following is not characteristic of Planck's quantum theory of radiation –

1. The energy is not absorbed or emitted in whole numbers or multiples of quantum.

2. Radiation is associated with energy.

3. Radiation energy is not emitted or absorbed continuously but in the form of small packets called quanta.

4. Magnitude of energy associated with a quantum is proportional to the frequency.

 3p orbital has -

1. Two spherical nodes

2. Two non-spherical nodes

3. One spherical and one non-spherical node

4. One spherical and two non-spherical nodes

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

^{1. 5}

^{2. 6}

^{3. 3}  

^{4. 4}

The wavelength of the photoelectric threshold of metal is 230 nm. Determine the K.E. of photoelectron ejected from the surface by UV radiation emitted from the second-longest wavelength transition (downward) of an electron in Lyman series of the atomic spectrum of hydrogen. (R=1.09677 x 107 m^-1)

1. 1.074 x 10^-18 J

2. 1.937 x 10^-18J

3. 6.213 × 10^-18 J

4. 7.123 x 10^-10J

The increasing order of energy of electromagnetic radiation can be represented as: 

Arrange the following particles in increasing order of values of e/m ratio: Electron(e), proton(p), neutron(n) and α-particle(α)

1. n,p,e,α

2. n,α,p,e

3. n,p,α,e

4. e,p,n,α

For the energy levels in an atom, which one of the following statements is correct -

1. There are seven principal electron energy levels

2. The second principal energy level can have two 'sub energy levels and contains a maximum of eight electrons

3. The energy level can have a maximum of 32 electrons

4. The 4s sub-energy level is at higher energy than the 3d sub-energy level