Find the wavelength of the balmer series spectral line corresponding to n = 15.

371.2 mm

Explanation:

The Balmer series of spectral lines is obtained from the formula

1/λ = R (1/2² - 1/n²) where λ = wavelength, R = Rydberg's constant = 1.097 * 10⁷ m⁻¹

when n = 15

1/λ = 1.097 * 10⁷ m⁻¹ (1/2² - 1/15²)

= 1.097 * 10⁷ m⁻¹ (1/4 - 1/225)

= 1.097 * 10⁷ m⁻¹ (0.25 - 0.0044)

= 1.097 * 10⁷ m⁻¹ 0.245556

= 2.693 10⁶ m⁻¹

So,

λ = 1/2.693 10⁶ m⁻¹

= 0.3712 10⁻⁶ m

= 371.2 mm