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Answer» Answer: f = 8.225 × 10 14 l Hz
Explanation: The Balmer SERIES corresponds to all electron transitions from a higher ENERGY LEVEL to n = 2 .
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The wavelength is given by the Rydberg formula
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ∣ ∣ ∣ ∣ a a 1 λ = R ( 1 n 2 1 − 1 n 2 2 ) a a ∣ ∣ ∣ ∣ −−−−−−−−−−−−−−−−−−−−−−−
where
R = the Rydberg constant and n 1 and n 2 are the energy levels such that n 2 > n 1
Since f λ = c
we can re-write the equation as
1 λ = f c = R ( 1 n 2 1 − 1 n 2 2 )
or
f = c R ( 1 n 2 1 − 1 n 2 2 ) = R ′ ( 1 n 2 1 − 1 n 2 2 )
where R ′ is the Rydberg constant expressed in energy units ( 3.290 × 10 15 l Hz ).
In this PROBLEM, n 1 = 2 , and the FREQUENCY of the limiting line is reached as n → ∞ .
Thus,
f = lim n → ∞
R ′ ( 1 4 − 1 n 2 2 ) = R ′ ( 0.25 − 0 ) = 0.25 R ′
= 0.25 × 3.290 × 10 15 l Hz = 8.225 × 10 14 l Hz
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