Which electron in a bromine (Br) atom experiences the lowest effective nuclear charge?
1. 2p and 3p
2. 4p
3. 2p
4. 3p

Among the following pairs of orbitals the orbital that will experience the larger effective nuclear charge respectively is -

(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 Al and Si are present in the 3p orbital. The electrons that will experience a more effective nuclear charge from the nucleus are :

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. Electrons in the 5p orbital of silicon

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:

The atomic number of elements whose outermost electronic configuration are represented by 3s¹ and 2p⁵ respectively, is:

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

The neon gas emits radiation of 616 nm. The number of quanta that are present in 2 J of energy is:

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: