Question

The energy of a photon of light with wavelength $5000\stackrel{\circ }{A}$ is approximately 2.5 eV. This way the energy of an X-ray photon with wavelength $1\stackrel{\circ }{A}$ would be

• A. $\frac{2.5}{5000eV}$
• B. $\frac{2.5}{(5000{)}^{2}eV}$
• C. $2.5\times 5000eV$
• D. $2.5\times (5000{)}^{2}eV$

Answer 1

The correct option is C

$2.5\times 5000eV$

$E\propto \frac{1}{\lambda }\Rightarrow \frac{2.5}{E^{\prime }}=\frac{1}{5000}\Rightarrow E^{\prime }=\left(2.5\right)\times 5000eV$