Question

is the wavelength of photon of energy $35 \,Kev$. $h=6.625 \times 10^{-34} J -s, c=3 \times 10^{8} \,m / s , 1 \,eV =1.6 \times 10^{-19} J$.

• A. $35 \times 10^{-12} m$
• B. $35 \,\mathring{A}$
• C. $3.5 \,nm$
• D. $3.5 \,\mathring{A}$

Answer 1

Answer: (A)

$ \lambda =\frac{h_{c}}{E_{\lambda}}=\frac{6.625 \times 10^{-34} \times 3 \times 10^{8}}{355 \times 10^{3} \times 1.6 \times 10^{-19}} m$
$=0.35 \times 10^{-10} m=3 \times 10^{-12} m$