Question

In terms of Rydberg's constant R, the wave number of the first Balmer line is
(a) R
(b) 3R
(c) $\frac{5R}{36}$
(d) $\frac{8R}{9}$

Answer 1

opt (c) 5R/36 wave number of first balmer line

Answer 2

Answer:

5R / 36

Explanation:

The value of the Rydberg constant R∞ is 1.097 × 10`7 per metre. When used in this form in various mathematical description of series of spectral lines, the result is always the number of waves per unit length, or the numbers of waves. The multiplication by the speed of light yields the frequencies of the spectral lines.

Thus, the Rydberg formula is used to predict the wavelength of light that results from an electron moving between the energy levels of an atom.

Wave number = (1 / λ) = R[(1 / 2²) – (1 / n²)]

Blamer series For 1st line, n = 3

Therefore, (1 / λ) = R[(1 / 4) – (1 / 9)]

= 5R / 36

Thus, the wave number of the first Balmer line is 5R / 36.