Assertion (A):	The angular momentum of an electron in an atom is quantized.
Reason (R):	In an atom, only those orbits are permitted in which the angular momentum of the electron is a natural number multiple of h/2π.

 

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
3.	(A) is True but (R) is False.
4.	(A) is False but (R) is True.

If the electronic structure of oxygen atom is written as $1{\mathrm{s}}^2, 2{\mathrm{s}}^2$  it would violate:

1. Hund's rule.

2. Paulis exclusion principle.

3. Both Hund's and Pauli's principles.

4. None of the above.

The mass and charge of one mole of electrons are, respectively:

1. 5.48 × ${10}^{-7}$ kg, 9.65 C, 
2. 5.48 × ${10}^{-7}$ C, 1.098 × 10²⁷
3. 5.48 × ${10}^{-7}$ kg, 9.65 × ${10}^4$ C
4. 9.65 × ${10}^4$ C, 1.098 × 10²⁷

The ratio of the wavelengths of the last lines of the Balmer to Lyman series is

The maximum number of neutrons are present in the nuclei of:

$1.$ ${\mathrm{O}}_8^{16}$
$2.$ ${\mathrm{Mg}}_{12}^{24}$
$3.$ ${\mathrm{Fe}}_{26}^{56}$
$4.$ ${\mathrm{Sr}}_{38}^{88}$

The complete symbol for the atom with the given atomic number (Z) and atomic mass (A) would be, respectively :

1.  ${}_4{}^9\mathrm{Be}$   ${}_{92}{}^{233}\mathrm{U}$     ${}_4{}^9\mathrm{Be}$

2.  ${}_{17}{}^{35}\mathrm{Cl}$    ${}_{92}{}^{233}\mathrm{U}$    ${}_4{}^9\mathrm{Be}$

3.  ${}_4{}^9\mathrm{Be}$    ${}_{17}{}^{35}\mathrm{Cl}$     ${}_{92}{}^{233}\mathrm{U}$

4. ${}_{92}{}^{233}\mathrm{U}$    ${}_4{}^9\mathrm{Be}$    ${}_{17}{}^{35}\mathrm{Cl}$