The faster an electron is moving, the _________ its kinetic energy, and the __________ its wavelength.

Consider the relationship between the speed of an electron and its wavelength. According to the de Broglie wavelength formula: $\lambda =\frac{h}{p}$, where $\lambda$ is the wavelength, $h$ is Planck's constant, and $p$ is the momentum. Momentum is the product of mass and velocity, $p=mv$. As velocity increases, momentum increases, leading to a decrease in wavelength.