Question

What is the wavelength of an X-ray photon with energy 8.0 keV (8000 eV)? (1 eV = 1.60 × 10−19 joule.)

Answer 1

Answer:

Wavelength = 0.15 nm

Frequency = $1939.3939\times 10^{15}Hz$

Explanation:

We have given photon energy E = 8 KeV = 8000 eV

In question it is given that $1eV=1.6\times 10^{-19}J$

So $8000eV=1.6\times 8000\times 10^{-19}=12800\times 10^{-19}j$

Plank's constant $h=6.6\times 10^{-34}js$

We know that photon energy is given by $E=h\nu$

So $12800\times 10^{-19}=6.6\times 10^{-34}\nu$

$\nu =1939.3939\times 10^{15}Hz$

Now wavelength $\lambda =\frac{c}{f}=\frac{3\times 10^8}{1939.3939\times 10^{15}}=0.0015\times 10^{-7}m=0.15nm$