An element X has the following isotopic composition: 
²⁰⁰X: 90% 
¹⁹⁹X: 8.0% 
²⁰²X: 2.0% 
The weighted average atomic mass of the naturally-occurring element X is closest to:

1. 200 amu
2. 201 amu
3. 202 amu
4. 199 amu

4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is:

Which of the following series of transitions in the spectrum of hydrogen atoms falls in the visible region?

1. Brackett series

2. Lyman series

3. Balmer series

4. Paschen series

The orbital diagram in which both Pauli's exclusion principle and Hund's rule are violated is: 
 

1.
2.
3.
4.

If the electronic structure of oxygen atom is written as $1{\mathrm{s}}^2,<mspace\; width="1em"></mspace>2{\mathrm{s}}^2$  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 correct order of the total number of nodes of atomic orbitals is: 

1.  4f > 6s > 5d

2.  6s > 5d > 4f

3.  4f > 5d > 6s

4.  5d > 4f > 6s

Correct statement among the following is: 

1.  Number of angular nodes = n - l - 1

2.  Number of radial nodes = l

3.  Total number of nodes = n -1

4.  All of the above

Which orbital has the maximum number of total nodes?
1.  5s

2.  5p

3.  5d

4.  All have the same number of nodes.

Orbitals having two spherical nodes are: 

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

1.  $\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{x}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{y}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{z}}^2}+\frac{8{\mathrm{\pi }}^2}{{\mathrm{mh}}^2}\left(\mathrm{E}-\mathrm{V}\right)<mspace\; width="1em"></mspace>\mathrm{\psi }=0$

2.  $\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{x}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{y}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{z}}^2}+\frac{8\mathrm{\pi m}}{{\mathrm{h}}^2}\left(\mathrm{E}-\mathrm{V}\right)<mspace\; width="1em"></mspace>\mathrm{\psi }=0$

3.  $\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{x}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{y}}^2}+\frac{{\partial }^2\mathrm{\psi }}{\partial {\mathrm{z}}^2}+\frac{8{\mathrm{\pi }}^2\mathrm{m}}{{\mathrm{h}}^2}\left(\mathrm{E}-\mathrm{V}\right)<mspace\; width="1em"></mspace>\mathrm{\psi }=0$

4.  None of the above.