Whleh color of light has photons of greater frequency, green or blue? 2. The mos
ID: 551885 • Letter: W
Question
Whleh color of light has photons of greater frequency, green or blue? 2. The most prominent line in the spectrum of magnesium is 285.2 nm. Other lines are found at 383.8 and 518.4 nm. a) In what region of the electromagnetic spectrum are these lines found? b) What is the frequency of the light with the wavelength of the least energetic linse? c) What is the energy of 1 photon of the light with the wavelength of the most energetic line? 3. An energy of 2.0 x 10 kJ/mol is required to cause cesium atoms on a metal surface to lose their electrons. Calculate the longest possible wavelength of light that can ionize a cesium atom. In what region of the electromagnetic spectrum is this radiation found? (Hint: First determine, in order to ionize one cesium atom, what is the minimum energy of ONE photon. Why?) 4. A hydrogen atom is excited by causing an electronic transition from (i) n 2 to n 3 and (ii) n 3 to n 4 principle energy level.Explanation / Answer
a)
these lines are prsent mainly on --> UV light = 285.2 nm; 383.8 nm
other lines --> 518.4 nm is in the visible spectrum
b)
frequency can be related as
WL = c/v
v = c/WL
for the least energetic --> highest Wavleneght
v = (3*10^8)/(518.4*10^-9) = 5.787*10^14 Hz
c)
energy of 1 photon of light of the most energetic
E = hv
h = Planck Constant = 6.626*10^-34 J s
v = c/WL (3*10^8)/(285.2*10^-9) = 1.0518*10^15
E = ( 6.626*10^-34)(1.0518*10^15) = 6.96*10^-19 J/photon
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.