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Calculate Wavelength N 4 N 2

Reviewed by Calculator Editorial Team

Calculate the wavelength of the n=4 to n=2 transition in hydrogen using the Rydberg formula. This calculator provides precise results and visualizations to help understand atomic spectroscopy.

Introduction

The n=4 to n=2 transition in hydrogen is a fundamental spectroscopic transition that emits light in the visible spectrum. This transition occurs when an electron in a hydrogen atom drops from the fourth energy level to the second energy level.

Understanding this transition is crucial in atomic physics, spectroscopy, and quantum mechanics. The wavelength emitted during this transition can be calculated using the Rydberg formula, which relates the wavelength to the energy levels involved.

Formula

The wavelength (λ) of the n=4 to n=2 transition in hydrogen can be calculated using the Rydberg formula:

λ = 1 / (R∞ × (1/n12 - 1/n22))

Where:

  • R∞ = Rydberg constant (1.0973731568508 × 107 m-1)
  • n1 = 4 (initial energy level)
  • n2 = 2 (final energy level)

The Rydberg constant is a fundamental physical constant that relates to the wavelengths of spectral lines of many chemical elements.

Calculation

To calculate the wavelength of the n=4 to n=2 transition:

  1. Identify the initial and final energy levels (n1 = 4, n2 = 2)
  2. Use the Rydberg constant (R∞ = 1.0973731568508 × 107 m-1)
  3. Plug the values into the formula: λ = 1 / (R∞ × (1/42 - 1/22))
  4. Calculate the result to find the wavelength in meters

The result will be in meters. You can convert this to nanometers by multiplying by 109.

Examples

Here's a worked example of calculating the wavelength for the n=4 to n=2 transition:

Example Calculation:

Given:

  • n1 = 4
  • n2 = 2
  • R∞ = 1.0973731568508 × 107 m-1

Calculation:

λ = 1 / (1.0973731568508 × 107 × (1/16 - 1/4))

λ = 1 / (1.0973731568508 × 107 × (0.0625 - 0.25))

λ = 1 / (1.0973731568508 × 107 × (-0.1875))

λ = -8.5185 × 10-8 m

Since wavelength cannot be negative, we take the absolute value:

λ = 8.5185 × 10-8 m

Convert to nanometers:

λ = 8.5185 × 10-8 × 109 = 85.185 nm

This calculation shows that the wavelength of the n=4 to n=2 transition in hydrogen is approximately 85.185 nanometers.

FAQ

What is the Rydberg formula used for?

The Rydberg formula is used to calculate the wavelengths of spectral lines of atoms, particularly hydrogen. It helps predict the wavelengths emitted or absorbed during electronic transitions between energy levels.

Why is the wavelength negative in the calculation?

The negative sign in the calculation indicates that the transition is from a higher energy level to a lower one, which results in the emission of energy (light). The absolute value is taken to represent the actual wavelength.

What is the significance of the n=4 to n=2 transition?

The n=4 to n=2 transition is significant because it produces light in the visible spectrum (red-orange region), which is commonly observed in hydrogen emission spectra. This transition is used in various applications, including spectroscopy and quantum mechanics.