Green light has a wavelength of 5200 A. How do you calculate the energy of one photon of green light?
1 Answer
Explanation:
We're asked to calculate the energy of one photon of a green light, given its wavelength of
To do this, we can use the equation
ul(E = (hc)/f
where
-
E is the energy of the photon (in joules) -
h is Planck's constant, equal to6.626xx10^-34 "J"•"s" -
c is the speed of light in vacuum,299792458 "m/s" -
f is the frequency of the photon (in meters)
We need to convert from ångströms to meters, using the conversion factor
1 "m" = 10^10 "Å" :
5200cancel("Å")((1color(white)(l)"m")/(10^10cancel("Å"))) = color(red)(ul(5.2xx10^-7color(white)(l)"m"
The energy of the photon is thus
color(blue)(E) = ((6.626xx10^-34color(white)(l)"J"•cancel("s"))(299792458cancel("m/s")))/(color(red)(5.2xx10^-7cancel("m"))) = color(blue)(ulbar(|stackrel(" ")(" "3.8xx10^-19color(white)(l)"J"" ")|) rounded to
2 significant figures.