Final answer:
The Balmer-Rydberg equation is a formula that predicts the wavelengths of hydrogen's emission spectrum, initially for visible light (Balmer series) and later expanded to include UV and IR ranges.
Step-by-step explanation:
Balmer-Rydberg Equation
The Balmer-Rydberg equation is a formula that describes the wavelengths of the emission spectrum of hydrogen. It was initially discovered by Johann Balmer in 1885 for the visible range and later generalized by Johannes Rydberg to predict wavelengths in the ultraviolet and infrared regions as well. The equation takes the form:
λ = R × (1/n₁² - 1/n₂²)
where λ is the wavelength, R is the Rydberg constant (1.097 x 10⁷ m⁻¹), and n₁ and n₂ are integers with n₁ < n₂. Balmer's work was specific to the visible light range (n₁ = 2, n₂ = 3, 4, 5, ...), and is known as the Balmer series. Rydberg expanded this to include other series such as the Lyman series (n₁ = 1) in the UV range, and the Paschen series (n₁ = 3) in the IR range.