(i)
Fig. Shapes of d-orbitals
(ii) Heisenberg's uncertainty principle:
It is impossible to measure simultaneously the position and momentum of a small particle with absolute accuracy or certainty.
The product of the uncertainty in the position (∆x) and the uncertainty in the momentum (∆p = m. ∆v , where m is the mass of the particle and v is the uncertainly in velocity) is always constant and is equal to or greater then \(\frac{h}{4\pi}\) , where h is a Planck’s constant, i.e.,
∆x ∆p ≥ \(\frac{h}{4\pi}\)