Question

structure and properties of matter question:

the emission spectrum of an unknown element contains two lines- one in the visible portion of the spectrum, and the other, ultraviolet. based on the following figure and on what you have learned about niels bohrs model of the atom, account for the difference in energy between these lines.

Wavelength Longer Shorter Cosmic rays Gamma rays Ultraviolet X-rays light Visible Infrared Radio waves light Radar AM FM/TV

Answer 1

the Eohr's model of the atom suggests that colours in line spectra are emitted by electrons. The differance between these two lines is because of electrons trans- - sitioning from higher orbitals to lower orbitals. *. According to Bohr, the line in the visible position to electron transition from higher Srbitaly to n=orbital which is called "bepaan tarins "Balmer series! * The line visible in uv portem of spectrum corresponds to electron transition from higher abitats i to na abital which is called "Lyman Series". nas T nas t naq Wh It haze 2 -123 n=2 =1 Series Balmer Series Lyman The Energy emitted during transition equal to difference in energy between 2 bits DE = Efter Einitial = Rhein-W) where, k= Rydberg constant 1 h = plank's constant c= speed of light when election moves from sobit na to abitin,

Fa our convinience, here we can say the line in the visible spectrum can be described as an electron Francitening from the 5th orbital (n.5) down to the second arbital (n=2) and the line occurs in or region can be an electron transitioning from the 6th orbital (66) down to the second (n=2). 1 Since Ultraviolet (v) light has greator Energy and as a result, takes more energy to produce. Therefore, "The electron transition responsible for producing á line in uv light must be larger than the transition responsible for producing a line in visible region".