The diffraction of an electron beam indicates that:

The de-Broglie wavelength $(\lambda)$ for electron $(e)$, proton $(p)$ and $He^{2+}$ ion $(\alpha)$ are in the following order. (Speed of $e$, $p$ and $\alpha$ are the same)

If the kinetic energy of an electron of mass $9.0 \times 10^{-31} \ kg$ is $2.0 \times 10^{-25} \ J$,the wavelength of the electron in $nm$ is approximately (in $.3$)

The basis of the quantum mechanical model of an atom is:

What is the characteristic of an electron microscope? On which principle is it based?

$C_{60}$ emerging from a source at a speed $(v)$ has a de Broglie wavelength of $11.0 \ \mathring{A}$. The value of $v$ (in $m \ s^{-1}$) is closest to
[Planck's constant $h = 6.626 \times 10^{-34} \ J \ s$]