Write down Heisenberg's uncertainty principle.

(N/A) Werner Heisenberg,a German physicist in $1927$,stated the uncertainty principle.
Principle: It states that it is impossible to determine simultaneously the exact position and exact momentum (or velocity) of an electron.
Mathematically,it is given by the equation:
$(\Delta x) \times (\Delta p) \geq \frac{h}{4 \pi}$ (Eq. $2.31$) or $(\Delta x) \times \Delta(m v_x) \geq \frac{h}{4 \pi}$
$(\Delta x) \times (m \Delta v_x) \geq \frac{h}{4 \pi}$ (Eq. $2.32$)
Where,
$\Delta x = \text{uncertainty in position of particle}$
$\Delta p = \text{uncertainty in momentum of particle}$
$\Delta v_x = \text{uncertainty in velocity of particle}$
Explanation: If the position of the electron is known ($\Delta x$ is small),then the velocity of the electron will be uncertain (large). If the velocity of the electron is known precisely,then the position of the electron will be uncertain. Thus,any physical measurement of the electron's position or velocity will always result in a fuzzy or blurred picture.
Significance: One of the important implications of the Heisenberg Uncertainty Principle is that it rules out the existence of definite paths or trajectories of electrons and other similar sub-atomic particles. Since it is not possible to simultaneously determine the position and velocity at any given instant to an arbitrary degree of precision,it is not possible to define the trajectory of an electron.