The line spectrum for element X includes a band of green light of wavelength 522 nm. This band corresponds to what energy transition within an atom of element X? Let Planck’s constant h = 4.136 × 10−15 eV ∙ s, and the speed of light c = 3.00 × 108 m/s.

1 Answer
May 25, 2017

decrease of 2.382.38 "e V"e V

Explanation:

Let's substitute the value of hh into the Planck equation E = h fE=hf:

Rightarrow E = (4.136 times 10^(- 15)E=(4.136×1015 "e V"e V cdot "s")s) times f×f

Then, let's substitute the definition of ff, f = frac(c)(lambda)f=cλ, into the above equation:

Rightarrow E = (4.136 times 10^(- 15)E=(4.136×1015 "e V"e V cdot "s")s) times frac(c)(lambda)×cλ

Let's substitute the values of cc and lambdaλ into the equation:

Rightarrow E = (4.136 times 10^(- 15)E=(4.136×1015 "e V"e V cdot "s")s) times frac(3.00 times 10^(8) " m s"^(- 1))(522 " nm")×3.00×108 m s1522 nm

Rightarrow E = (4.136 times 10^(- 15)E=(4.136×1015 "e V"e V cdot "s")s) times frac(3.00 times 10^(8) " m s"^(- 1))(5.22 times 10^(- 7) " m")×3.00×108 m s15.22×107 m

Rightarrow E = frac(1.2408 times 10^(- 6) " e V" cdot "m")(5.22 times 10^(- 7) " m")E=1.2408×106 e Vm5.22×107 m

Rightarrow E = 2.337E=2.337 "e V"e V

therefore E = 2.38 "e V"

Therefore, this band corresponds to a decrease of 2.38 "e V".