Dual nature of particles was proposed by

State the de-Broglie principle and explain it.

The wavelength associated with the motion of an electron:

If travelling at equal speeds,the longest wavelength of the following matter waves is that for a :

An electron has kinetic energy $2.8 \times 10^{-23} \ J$. The de-Broglie wavelength will be nearly $(m_e = 9.1 \times 10^{-31} \ kg)$.

If the radius of the first orbit of the $H$ atom is $a_0$, then the de Broglie wavelength of the electron in the third orbit will be ....... (in $\pi a_0$)