Hydrogen Energy Levels Calculator

Find the energy of a hydrogen electron's nth level.

Energy (eV) -3.401
Energy (J) 0

Formula: E_n = −13.6 ÷ n² eV

Step-by-step with your numbers:
1. Values used:
2. Principal quantum number n = 2
3.
4. Energy = -3.401eV
5. Energy = 0J
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Hydrogen's electron can occupy only discrete energy levels, set by the quantum number n.

How the Math Works

The Hydrogen Energy Levels Calculator uses the formula E_n = -13.6 ÷ n² eV, derived from the Bohr model of the hydrogen atom. This equation quantifies the energy of an electron in the nth quantized energy level. The negative sign indicates the electron is bound to the nucleus, with energy increasing (becoming less negative) as n increases. The constant 13.6 eV represents the ionization energy required to free the electron from the ground state (n=1). By substituting the principal quantum number (n), the calculator determines the electron's energy relative to an infinitely separated state (n→∞, E=0).

Practical Applications

This calculation is essential in atomic physics and chemistry to predict energy transitions when electrons move between levels. For example, when an electron drops from a higher to lower energy level, it emits a photon with energy equal to the difference between levels, which corresponds to specific spectral lines. This principle is used in spectroscopy to identify elements in stars or materials. It also aids in designing educational experiments, such as demonstrating the Franck-Hertz experiment, and in understanding quantum mechanics concepts like quantized energy states and electron orbitals.

Day-to-Day Use

While not directly applied daily, this concept underpins technologies we encounter regularly. For instance, LEDs and lasers rely on controlled electron energy transitions to emit specific wavelengths of light. In medical imaging like PET scans, understanding atomic energy levels helps analyze radioactive tracers. Additionally, research into hydrogen fusion as a future energy source depends on manipulating atomic states, and advancements in semiconductor devices for electronics benefit from quantum energy level modeling. Thus, the foundational knowledge supports innovations in lighting, computing, and clean energy research.

Worked example

n = 2 → −3.4 eV.

FAQ

Why negative?

Bound states have negative energy; zero corresponds to a free, just-escaped electron.