What are matter waves? A proton, an electron and an α -particle have the same kinetic energy. Write the de Broglie wavelengths associated with them…

The waves associated with every moving particle are called matter waves. $\displaystyle \lambda=\frac{h}{\sqrt{2 m K}}$ For same kinetic energy, $\displaystyle \lambda \propto \frac{1}{\sqrt{m}}$ $\displaystyle m_{\alpha}>m_{p}>m_{e}$ $\displaystyle \therefore \lambda_{\alpha}<\lambda_{p}<\lambda_{e}$