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For emission line of atomic hydrogen from n_i = 8 to n_f = n, the plot of wave number (̅ν) against (1/n²) will be (The Rydberg constant, R_H is wave number unit) (1) Linear with slope -R_H (2) Linear with slope R_H (3) Non linear (4) Linear with intercept -R_H

1. Linear with slope -R_H
2. Linear with slope R_H
3. Non linear
4. Linear with intercept -R_H

Correct answer: Linear with slope R_H

Solution

Wave number nu-bar = R_H(1/n_f^2 - 1/n_i^2) = R_H(1/n^2) - R_H/64. Plotting nu-bar against (1/n^2) gives a straight line of slope +R_H and intercept -R_H/64, so it is linear with slope R_H.

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