The energy equivalent to 1 amu., is :

• 931.1 MeV

• 1.492 x 10¹³ erg

• 1000 J

• 10⁷ erg

Which particle can be used to change ₁₃Al²⁷ into ₁₅P³⁰ ?

• Neutron

• $\mathrm{\alpha }$ - particle

• Proton

• Deuteron

According to Bohr, the angular momentum of an electron, in any orbit, should be :

• h/2$\mathrm{\pi }$

• nh/2$\mathrm{\pi }$

• h/mv

• 2$\mathrm{\pi }$/nh

Quantum numbers of an atom can be defined on the basis of :

• Hund's rule

• Pauli's exclusion principle

• Aufbau's principle

• Heisenberg's uncertainty principle

Which of the following has maximum energy ?

• 
  3s                      3p                                     3d

  $⥮$

  $⥮$

  $\uparrow$

  $\uparrow$

• 3s                      3p                                   3d

  $⥮$

  $\uparrow$

  $\uparrow$

  $\uparrow$

  $\uparrow$

• 3s                     3p                                     3d

  $⥮$

  $\uparrow$

  $\uparrow$

  $\uparrow$

  $\uparrow$

  $\uparrow$

• 3s                    3p                                 3d

  $⥮$

  $\uparrow$

  $\uparrow$

  $\uparrow$

  $\uparrow$

Spectrum of Li²⁺ is similar to that of :

• H

• Be

• He

• Ne

Azimuthal quantum number defines :

• e/m ratio of electron

• angular momentum of electron

• spin of electron

• magnetic momentum of electron

For principle quantum number n = 4, the total number of orbitals having l= 3 is

• 3

• 7

• 5

• 9

659.

Assertion : Nuclear binding energy per nucleon is in the order - ${}_4{}^9\mathrm{Be} >{}_3{}^7\mathrm{Li} >{}_2{}^4\mathrm{He}$

Reason : Binding energy per nucleon increases linearly with difference in number of neutrons and protons.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

The quantum number m of a free gaseous atom is associated with

• the effective volume of the orbital

• the shape of the orbital

• the spatial orientation of the orbital

• the energy of the orbital in the absence of a magnetic field.