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Structure Of Atom

Question
CBSEENCH11005293
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Emission transitions in the Paschen series end at orbit n = 3 and start from orbit n and can be represented as
v = 3.29 x 1015 (Hz) [1/32- l/n2.]

Calculate the value of n if the transition is observed at 1285 nm. Find the region of the spectrum.

Solution
space space space Here comma space space straight v space equals space 3.29 space cross times space 10 to the power of 15 left parenthesis Hz right parenthesis space open square brackets 1 over 3 squared minus 1 over straight n squared close square brackets space... left parenthesis 1 right parenthesis space Also comma space straight v equals space straight c over straight lambda space equals space fraction numerator 3.0 space cross times space 10 to the power of 8 space ms to the power of negative 1 end exponent over denominator 1285 space cross times 10 to the power of negative 9 end exponent straight m end fraction space space space space... left parenthesis 2 right parenthesis space From space equations space left parenthesis 1 right parenthesis space and space left parenthesis 2 right parenthesis comma space we space have space space space space 3.29 space cross times space 10 to the power of 15 open square brackets 1 over 3 squared minus 1 over straight n squared close square brackets space equals space fraction numerator 3.0 space cross times space 10 to the power of 8 over denominator 1285 space cross times 10 to the power of negative 9 end exponent end fraction space or space space space 1 over 9 minus 1 over straight n squared fraction numerator 3.0 space cross times space 10 to the power of 8 over denominator 1285 space cross times space 10 to the power of negative 9 end exponent space cross times space 3.29 space cross times space 10 to the power of 15 end fraction equals 0.071 space or space space 1 over straight n squared space equals space 1 over 9 minus 0.071 space equals space 0.111 minus 0.071 space space space space space space space space space space space equals space 0.04 space equals space 1 over 25 or space space space straight n squared space equals space 25 space space space or space space space straight n space equals space 5
The radiation corresponding to 1285 nm lies in the infra red region.

Some More Questions From Structure of Atom Chapter

Who discovered neutron?

What is a neutron?

What is the name of the remaining part of atom except outer orbit?

Name the particles which determine the mass of an element.

What are α-particles?

Why were neutrons discovered very late?

What are the fundamental particles present in a neutral atom having atomic number greater than 1?

Do protons and neutrons have identical mass?

When α-particles are sent through a thin metal foil, most of them go straight through the foil. What inference do you draw from it?

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