What does the hardness of $X$-rays obtained from an $X$-ray tube indicate?

The wavelength of ${K_{\alpha }}$ $X$-rays produced by an $X$-ray tube is $0.76 \, \mathring{A}$. The atomic number of the anticathode material is:

The ratio of the energy of an $X$-ray photon of wavelength $1 \mathring{A}$ to that of visible light of wavelength $5000 \mathring{A}$ is:

Molybdenum is used as a target element for the production of $X-$rays because it is

$STATEMENT-1$: If the accelerating potential in an $X$-ray tube is increased, the wavelengths of the characteristic $X$-rays do not change. because
$STATEMENT-2$: When an electron beam strikes the target in an $X$-ray tube, part of the kinetic energy is converted into $X$-ray energy.

$X$-rays incident on a material: