The uncertainty principle is

$$\Delta E \times \Delta t \ge {h \over {4\pi }}$$

Half filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement.

The energy of 2s-orbital is less than the energy of 2p-orbital in case of hydrogen like atoms.

de-Broglie's wavelength is given by

$$\lambda = {h \over {mv}}$$, where m = mass of the particle,

v $$=$$ group velocity of the particle.

2

6

10

14

$${d_{{z^2}}},\,\,{d_{xz}}$$

d_xz,  $${d_{yz}}$$

$${d_{{z^2}}},\,\,{d_{{x^2} - {y^2}}}$$

$${d_{xy}},\,{d_{{x^2} - {y^2}}}$$

azimuthal quantum number

spin quantum number

principal quantum number

magnetic quantum number