14
MCQ (Single Correct Answer)
The pair of ions having same electronic configuration is ............ .
A
$\mathrm{Cr}^{3+}, \mathrm{Fe}^{3+}$
B
$\mathrm{Fe}^{3+}, \mathrm{Mn}^{2+}+$
C
$\mathrm{Fe}^{3+}, \mathrm{Co}^{3+}$
D
$\mathrm{Sc}^{3+}, \mathrm{Cr}^{3+}$
15
MCQ (Single Correct Answer)
For the electrons of oxygen atom, which of the following statements is correct?
A
$Z_{\text {eff }}$ for an electron in a $2 s$ orbital is the same as $Z_{\text {eff }}$ for an electron in a $2 p$ orbital
B
An electron in the $2 s$ orbital has the same energy as an electron in the $2 p$ orbital
C
$Z_{\text {eff }}$ for an electron in $1 s$ orbital is the same as $Z_{\text {eff }}$ for an electron in a $2 s$ orbital
D
The two electrons present in the $2 s$ orbital have spin quantum numbers $m_s$ but of opposite sign
16
MCQ (Single Correct Answer)
If travelling at same speeds, which of the following matter waves have the shortest wavelength?
A
Electron
B
Alpha particle $\left(\mathrm{He}^{2+}\right)$
C
Neutron
D
Proton
17
MCQ (Multiple Correct Answer)
Identify the pairs which are not of isotopes?
A
${ }_6^{12} X,{ }_6^{13} Y$
B
${ }_{17}^{35} X,{ }_{17}^{37} Y$
C
${ }_6^{14} X,{ }_7^{14} Y$
D
${ }_4^8 X,{ }_5^8 Y$
18
MCQ (Multiple Correct Answer)
Out of the following pairs of electrons, identify the pairs of electrons present in degenerate orbitals.
A
(i) $n=3, l=2, m_l=-2, m_s=-\frac{1}{2}$
(ii) $n=3, l=2, m_l=-1, m_s=-\frac{1}{2}$
B
(i) $n=3, l=1, m_l=1, m_s=+\frac{1}{2}$
(ii) $n=3, l=2, m_l=1, m_s=+\frac{1}{2}$
C
(i) $n=4, l=1, m_l=1, m_s=+\frac{1}{2}$
(ii) $n=3, l=2, m_l=1, m_s=+\frac{1}{2}$
D
(i) $n=3, l=2, m_l=+2, m_s=-\frac{1}{2}$
(ii) $n=3, l=2, m_l=+2, m_s=+\frac{1}{2}$