Question

Which one is the wrong statement?


<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> NEET 2017

Answer 1

(a) For a single electronic species like H, energy depends on value of n and does not depend on l.
Hence, energy of 2s and 2p orbital is equal of H-like species. Therefore (A) is incorrect.
(b)According to de-Broglie's equation, wavelength
$\lambda =\frac{h}{mv}$, where h is planck's constant.
Therefore (B) is correct.

(c) According to Heisenberg uncertainity principle, the uncertainity in position $\left(\Delta x\right)$ and momentum $\left(m\Delta v\right)$ is given by
$\Delta x.\Delta p\ge \frac{h}{4\pi }$
$\Delta x.m\Delta v\ge \frac{h}{4\pi }$
$\Delta x.m\Delta a\Delta t\ge \frac{h}{4\pi }$
$\Delta x.F\Delta t\ge \frac{h}{4\pi }$
$\Delta E.\Delta t\ge \frac{h}{4\pi }$
Statement (C) is correct.

(d) The half and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement. Therefore (D) is correct.