Wave Particle Duality

This means that light could behave as wave and also as particle i.e. Light behave either as wave or as a particle but not as both simultaneously. 

Uncertainty Principle

Heisenberg stated that the momentum and position of a particle cannot be correctly located or measured at the same time. The more accurate the position determined, the less accurate the momentum at the same time. Therefore, Heisenberg uncertainty principle states that the product of uncertainty in the measurements of position (∆x) and momentum (∆p) of a particle is equal to or greater than the Planck’s constant (h).

Mathematically,

∆x∆p ≥ h

∆x – uncertainty in position, ∆p – uncertainty in momentum

h – Planck’s constant

This is also true for measurements of energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit... More ∆E and time ∆t

∆E.∆t ≥h

Example

What is uncertainty in momentum of a particle if uncertainty in position is 5.0×10^-8m

Solution

∆x.∆P ≥h

∆p ≥ \( \frac{h}{\Delta x} = \frac{6.6 \times 10^{-34}}{5 \times 10^{-8}}\)

∆p ≥ 1.32 x 10^-26 kgms^-1.