Sodium vapor lamps produce an intense light of a characteristic color.. The emit
ID: 1049533 • Letter: S
Question
Sodium vapor lamps produce an intense light of a characteristic color.. The emitted light is caused by electrons undergoing a transition from an excited state to a ground state. The light has a wavelength of 589 nm. Other lights use mercury vapor as a source. One of the most intense lines in the emission of a mercury lamp occurs with a wavelength of 253.7nm. What color is the light emitted from the Na atoms in the lamp? What is the name of the spectral region in which the light is emitted from the Hg atom in the lamp? Can this light be seen by human eyes? Calculate the frequency and energy of the emission lines from these two lamps.Explanation / Answer
A)
589 nm is yellow in color
B)
This is ultraviolet .
It can’t be seen by human eyes
C)
for sodium vapour light,
wavelength = 589*10^-9 m
f = c/lambda
= (3*10^8)/(589*10^-9)
=5.09*10^14 Hz
E = h*f
= (6.626*10^-34 * 5.09*10^14)
= 3.37*10^-19 J
for MERCURY LAMP,
wavelength = 253.7*10^-9 m
f = c/lambda
= (3*10^8)/(253.7*10^-9)
=1.18 *10^15 Hz
E = h*f
= (6.626*10^-34 * 1.18*10^15)
= 7.83 *10^-19 J