For each of the following pairs of atomic orbitals, identify the one that experiences a larger effective nuclear charge (\(Z_{\text{eff}}\)):

(i) 2s and 3s, (ii) 4d and 4f, (iii) 3d and 3p.

1. 2s, 4d, 3p

2. 3s, 4f, 3d

3. 3s, 4f, 3p

4. 2s, 4d, 3d

The unpaired electrons in aluminium and silicon occupy 3p orbitals in their ground states. Which of the following experiences a greater effective nuclear charge?

1. Electrons in the 3p orbital of silicon

2. Electrons in the 5d orbital of aluminium

3. Electrons in the 3p orbital of aluminium

4. Both experience the same effective nuclear charge

 

Identify the element with the highest number of unpaired electrons in its ground state from the given options :

The number of electrons that can be present in the subshells having m_s value of \(-\frac{1}{2}\) for n = 4 are:

Which of the following gives the atomic numbers of the elements having outermost electronic configurations 3s¹ and 2p⁵, respectively?

The circumference of the Bohr orbit for the H atom is related to the de Broglie wavelength associated with the electron revolving around the orbit by the following relation: 
1. $2\mathrm{\pi r}=\mathrm{n\lambda }$
2. $\mathrm{\pi r}$ $=$ $2\mathrm{n\lambda }$
3. $\mathrm{mvr}$ $=$ $\mathrm{n\lambda }$
4. $\mathrm{vr}$ $=$ $2\mathrm{n\lambda }$

Which among the following are isoelectronic species?

1. ${\mathrm{Na}}^{+},<mspace\; width="1em"></mspace>{\mathrm{K}}^{+},<mspace\; width="1em"></mspace>{\mathrm{Ca}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Mg}}^{2+}$

2. ${\mathrm{Ca}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Mg}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{S}}^{2-},<mspace\; width="1em"></mspace>{\mathrm{K}}^{+}$

3. ${\mathrm{Ca}}^{2+},<mspace\; width="1em"></mspace>\mathrm{Ar},<mspace\; width="1em"></mspace>{\mathrm{S}}^{2-},<mspace\; width="1em"></mspace>{\mathrm{K}}^{+}$

4. None of the above

Find the total number of photons emitted by neon gas if the radiation has a wavelength of 616 nm and a total energy of 2 J.
1. \(6.2 \times 10^{-18} \)
2. \(5.6 \times 10^{17} \)
3. \(6.2 \times 10^{18} \)
4. \(32.2 \times 10^{-20}\)

The ultraviolet region in the above figure is indicated by:

The graph that represents the variation of  ${\mathrm{\psi }}^2$ (probability of density of finding the electron) with distance (r) is given below:

The number of nodes as per the graph is:

1. zero

2. One

3. Two

4. Cannot predict