The radius of second stationary orbit in Bohr's atom is R. The radius of 3^rd orbit will be:-

1. 9R

2. R/4

3. 9R/4

4. 2R

Bohr's model is not valid for:-

(1) H-atom

(2) D-atom

(3) T-atom

(4) He-atom

Which of the following pairs of d-orbitals will have electron density along the axes?

1.  d_z²,d_xz

2.  d_xz,d_yz

3.  d_z²,d_x²-y²

4.  d_xy,d_x²-y²

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium?

(1) 3s 4s 3p 3d                   

(2) 4s 3s 3p 3d

(3) 3s 3p 3d 4s                   

(4) 3s 3p 4s 3d

What is the maximum numbers of electrons that can be associated with the following set of quantum numbers?

n=3, l = 1 and m=-1

(1) 10
(2) 6
(3) 4
(4) 2

Maximum number of electrons in a subshell 4f is

(1) 14
(2) 16
(3) 10
(4) 12

Which one of the following ions has electronic configuration [Ar]3d⁶?

(At. no: Mn = 25, Fe = 26, Co = 27, Ni =28)

(1) Ni³⁺               

(2) Mn³⁺

(3) Fe³⁺               

(4) Co³⁺

If the uncertainty in position and momentum are equivalent, what is the corresponding uncertainty in velocity?

The correct Schrodinger's wave equation for a electron with total energy E and potential energy V is given by

1.  $\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{x}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{y}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{z}}^2}+\frac{8{\mathrm{\pi }}^2}{{\mathrm{mh}}^2}\left(\mathrm{E}-\mathrm{V}\right) \mathrm{\psi }=0$

2.  $\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{x}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{y}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{z}}^2}+\frac{8\mathrm{\pi m}}{{\mathrm{h}}^2}\left(\mathrm{E}-\mathrm{V}\right) \mathrm{\psi }=0$

3.  $\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{x}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{y}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{z}}^2}+\frac{8{\mathrm{\pi }}^2\mathrm{m}}{{\mathrm{h}}^2}\left(\mathrm{E}-\mathrm{V}\right) \mathrm{\psi }=0$

4.  None of the above.

Which of the following expressions represents the spectrum of Balmer series (If n is the principal quantum number of higher energy level) in Hydrogen atom?

1.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-1\right) \left(\mathrm{n}+1\right)}{{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

2.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-2\right) \left(\mathrm{n}+2\right)}{4{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

3.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-2\right) \left(\mathrm{n}+2\right)}{{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

4.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-1\right) \left(\mathrm{n}+1\right)}{4{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$