Question

A bright line spectrum contains a line equivalent to a wavelength of 518 nm. Calculate the following:a. Wavelength (in meters)b. The frequency (in hertz)c. The energy, in joulesd. Use the spectrum to determine the color of the light

Answer 1

We will have the following:

a. Wavelength in meters.

We know that 1 meter contains 1*10^9 nanometers, so:

$\lambda=518nm\cdot\frac{1m}{1\cdot10^9nm^{}}\Rightarrow\lambda=5.18\cdot10^{-7}m$

b.The frequency:

$5.18\cdot10^{-7}m=\frac{3.0\cdot10^8m/s}{f}\Rightarrow f=\frac{3.0\cdot10^8m/s}{5.18\cdot10^{-7}m}$$\Rightarrow f=5.79\cdot10^{14}Hz$

c. The energy: in Joules

$E=(6.62\cdot10^{-34}m^2Kg/s)(5.79\cdot10^{14}/s)\Rightarrow E=3.83\cdot10^{-19}m^2Kg/s^2$$\Rightarrow E=3.83\cdot10^{-19}\cdot m^2Kg/s^2\cdot(J/m^2Kg/s^2)\Rightarrow E=3.83\cdot10^{-19}J$

d. The color range in which a wavelength of 518nm is located is in the Green.