1 angstrom corresponds to approximately 12.3984 electronvolts (eV).
Table of Contents
This conversion is based on the relationship between wavelength measured in angstroms and photon energy measured in electronvolts. Since energy and wavelength are related through Planck’s constant and the speed of light, converting from angstroms (a unit of length) to eV (a unit of energy) involves using these physical constants.
Conversion Tool
Result in ev:
Conversion Formula
The formula to convert wavelength λ in angstroms to photon energy E in electronvolts is:
E (eV) = 12398.4193 / λ (angstrom)
This formula comes from the energy-wavelength relation for photons: E = hc / λ, where h is Planck’s constant (~6.626×10⁻³⁴ Js), c is the speed of light (~3×10⁸ m/s), and λ is wavelength in meters. To work with angstroms and electronvolts, the constants are combined to a single factor 12398.4193.
Example: For λ = 1 angstrom,
- Calculate E = 12398.4193 / 1 = 12398.4193 eV
- Which is approximately 12.3984 keV (since 1 keV = 1000 eV)
Conversion Example
- Convert 2 angstroms to eV:
- Using formula: E = 12398.4193 / 2
- E = 6199.20965 eV
- This means a 2-angstrom wavelength photon has energy about 6.199 keV.
- Convert 0.5 angstroms to eV:
- E = 12398.4193 / 0.5
- E = 24796.8386 eV (24.796 keV)
- Shorter wavelengths have higher energies, as shown here.
- Convert 10 angstroms to eV:
- E = 12398.4193 / 10
- E = 1239.84193 eV (1.239 keV)
- Longer wavelengths correspond to lower photon energies.
- Convert 5 angstroms to eV:
- E = 12398.4193 / 5
- E = 2479.68386 eV (2.479 keV)
- This demonstrates the inverse proportionality between wavelength and energy.
Conversion Chart
The table below shows values from -24.0 to 26.0 angstroms and their equivalent energies in eV. Negative wavelengths don’t physically exist, but included here for completeness in mathematical sense.
| Angstrom (Å) | Energy (eV) |
|---|---|
| -24.0 | -516.601 |
| -20.0 | -619.921 |
| -16.0 | -774.901 |
| -12.0 | -1033.201 |
| -8.0 | -1549.803 |
| -4.0 | -3099.605 |
| -1.0 | -12398.419 |
| 1.0 | 12398.419 |
| 4.0 | 3099.605 |
| 8.0 | 1549.803 |
| 12.0 | 1033.201 |
| 16.0 | 774.901 |
| 20.0 | 619.921 |
| 24.0 | 516.601 |
| 26.0 | 476.862 |
To use this chart, find the angstrom value closest to your wavelength and read corresponding energy in eV. For better accuracy, use the formula or conversion tool.
Related Conversion Questions
- How many electronvolts does 1 angstrom wavelength correspond to?
- What is the energy in eV for a photon with 1 angstrom wavelength?
- Can 1 angstrom be converted directly to electronvolts without a calculator?
- Why does 1 angstrom equal about 12,398 eV in energy?
- How do I calculate eV from 1 angstrom wavelength manually?
- Is the conversion from angstrom to eV linear at 1 angstrom?
- What physical constants are needed to convert 1 angstrom to electronvolts?
Conversion Definitions
Angstrom: An angstrom is a unit of length equal to 10⁻¹⁰ meters, commonly used to measure atomic-scale distances such as wavelengths of X-rays or sizes of atoms. It provides convenient scale for expressing very small lengths in physics and chemistry.
eV (Electronvolt): Electronvolt is a unit of energy equal to the energy gained by an electron when it moves through an electric potential difference of one volt. It is frequently used in atomic and particle physics to express energies of photons, electrons, and other particles.
Conversion FAQs
Why does the conversion formula use the number 12398.4193?
This constant arises from multiplying Planck’s constant (h) and speed of light (c), then converting units from meters and joules to angstroms and electronvolts. Its value ensures the formula gives energy in eV when wavelength is in angstroms, simplifying calculations.
Can negative angstrom values be physically meaningful?
Negative wavelengths don’t exist physically, as wavelength is a positive length quantity. Negative values appear only in mathematical contexts or computational outputs but don’t correspond to real photon properties or energies.
Does the conversion apply to all types of waves?
The formula specifically applies to electromagnetic radiation, such as photons, where energy and wavelength relate by E=hc/λ. It does not apply to mechanical waves or particles without wave-like properties measured this way.
How accurate is the conversion formula for real-world applications?
The formula is very accurate for photon energies in fields like spectroscopy or X-ray crystallography. Minor variations can occur due to rounding constants, but the difference is negligible for most practical purposes.
Why are electronvolts preferred over joules in these conversions?
Electronvolts are a convenient unit for atomic and particle energies because their scale matches typical energy levels involved. Joules are too large, making electronvolts more practical for expressing energies at microscopic scales.