For an electron impossible combination of quantum number is

• n = 3; l = 2; m_l = -2; m_s = +$\frac{1}{2}$

• n = 3; l = 2; m_l = -3; m_s = +$\frac{\mathrm{}}{$ \frac{1}{2}$}$

• n = 4; l = 0; m_l = 0; m_s = -$\frac{1}{2}$

• n = 5; l = 3; m_l = 0; m_s = -$\frac{1}{2}$

The energy of an electron in n^th orbit of hydrogen atom is

• $\frac{13.6}{{\mathrm{n}}^4}\mathrm{eV}$

• $\frac{13.6}{{\mathrm{n}}^3}\mathrm{eV}$

• $-\frac{13.6}{{\mathrm{n}}^2}\mathrm{eV}$

• $\frac{13.6}{\mathrm{n}}\mathrm{eV}$

Which of the following is not iso-electronic?

• Na⁺

• Mg²⁺

• O^2-

• Cl^-

The number of unpaired electrons is maximum in (Atomic number Ti = 22; V= 23; Cr =24; Fe=26)

• Fe

• Cr

• Ti

• V

On moving from left to right in the second period along the periodic table the gram atomic volume of the element

• increases with constant velocity

• remains unchanged

• first increases and then decreases

• decreases

Which of the following is the correct order of the size of iodine species?

• I > I^- > I⁺

• I^- > I > I⁺

• I⁺ > I > I^-

• I > I⁺ > I^-

First ionisation potential of Be and B will be

• 8.8 and 8.8

• 6.6 and 6.6

• 6.6 and 8.8

• 8.8 and 6.6

Which of the following electronic configuration will have maximum IP difference between II^nd and III^rd ionisation potential?

• 1s², 2s² 2p⁶, 3s¹

• 1s², 2s² 2p⁶, 3s²

• 1s², 2s² 2p⁶

• 1s², 2s² 2p⁵

Which of the following is true for a reaction in which all the products are liquid?

• $∆\mathrm{H} = ∆\mathrm{E}$

• $∆\mathrm{H} = ∆\mathrm{W}$

• $∆\mathrm{H} > ∆\mathrm{E}$

• None of these

Cell reaction is spontaneous when

• $∆\mathrm{G}°$ is negative

• $∆\mathrm{G}°$ is positive

• $∆{\mathrm{E}}_{\mathrm{red}}^{°}$ is positive

• $∆{\mathrm{E}}_{\mathrm{red}}^{°}$ is negative