Understanding Ergs to Electronvolts Conversion
The erg is the unit of energy in the centimetre-gram-second (CGS) system, equal to one dyne acting through one centimetre, while the electronvolt (eV) is the kinetic energy gained by an electron accelerated through a potential difference of one volt. Because the electronvolt is a minuscule sub-atomic energy scale, a single erg equates to an enormous number of them. This conversion bridges macroscopic CGS laboratory energies and the particle-physics scale, useful when translating cross-section or reaction energies quoted in ergs into the eV units favoured in atomic and nuclear physics.
Conversion Formula
To convert Ergs to Electronvolts, multiply by this factor:
Step-by-Step Example
Convert 25 Ergs to Electronvolts.
How to Convert Ergs to Electronvolts
Converting an erg to electronvolts scales a CGS energy up to the particle-physics unit.
- Start with your erg value: Note the energy in ergs that you want to express in electronvolts.
- Apply the factor: Multiply the erg figure by 6.24151 \times 10¹¹, the number of electronvolts per erg.
- Read the result: The product is your energy in electronvolts; for 25 erg the result is 1.56038 \times 10¹³ eV.
Ergs to Electronvolts conversion table
| Ergs (erg) | Electronvolts (eV) |
|---|---|
| 0 | 0 |
| 1 | 624150900000 |
| 2 | 1248302000000 |
| 3 | 1872453000000 |
| 4 | 2496604000000 |
| 5 | 3120755000000 |
| 6 | 3744905000000 |
| 7 | 4369056000000 |
| 8 | 4993207000000 |
| 9 | 5617358000000 |
| 10 | 6241509000000 |
| 15 | 9362264000000 |
| 20 | 12483020000000 |
| 25 | 15603770000000 |
| 30 | 18724530000000 |
| 40 | 24966040000000 |
| 50 | 31207550000000 |
| 60 | 37449050000000 |
| 70 | 43690560000000 |
| 80 | 49932070000000 |
| 90 | 56173580000000 |
| 100 | 62415090000000 |
| 150 | 93622640000000 |
| 200 | 124830200000000 |
| 250 | 156037700000000 |
| 300 | 187245300000000 |
| 400 | 249660400000000 |
| 500 | 312075500000000 |
| 600 | 374490500000000 |
| 700 | 436905600000000 |
| 800 | 499320700000000 |
| 900 | 561735800000000 |
| 1000 | 624150900000000 |
| 2000 | 1248302000000000 |
| 3000 | 1872453000000000 |
| 4000 | 2496604000000000 |
| 5000 | 3120755000000000 |
| 10000 | 6241509000000000 |
| 25000 | 15603770000000000 |
| 50000 | 31207550000000000 |
| 100000 | 62415090000000000 |
| 250000 | 156037700000000000 |
| 500000 | 312075500000000000 |
| 1000000 | 624150900000000000 |
What is the Erg?
The erg is a unit of energy in the centimetre-gram-second (CGS) system, historically common in physics, astronomy, and mechanics before the SI joule became standard.
Definition
One erg is the work done by a force of one dyne acting over a distance of one centimetre:
This equals exactly one ten-millionth of a joule (10⁻⁷ J), or equivalently 1 g·cm²/s². The erg is a small unit, reflecting the small base units of the CGS system.
Origin and History
The name comes from the Greek ergon, meaning "work." The unit was formally adopted by the British Association for the Advancement of Science in 1873 as part of the CGS system and remained the dominant energy unit in physics literature well into the 20th century.
Law and Notable Facts
The erg has been largely superseded by the joule and is deprecated in the modern SI framework, but it persists in astrophysics, where luminosities and energies are still frequently quoted in ergs and erg per second.
Real-World Examples and Conversions
- 1 joule equals 10 million ergs.
- A mosquito in flight expends energy on the order of a few ergs per wingbeat.
- The Sun radiates about 3.8 × 10³³ ergs every second, equivalent to 3.8 × 10²⁶ watts.
What is the Electronvolt?
The electronvolt is a small unit of energy used throughout atomic, nuclear, and particle physics to describe the energies of individual particles, photons, and chemical or nuclear reactions.
Definition
One electronvolt is the kinetic energy gained by a single electron accelerated through an electric potential difference of one volt:
Since the 2019 redefinition of SI units, this value is exact: 1 eV = 1.602176634 × 10⁻¹⁹ J, because the elementary charge is now a defined constant. Common multiples include the keV (10³ eV), MeV (10⁶ eV), GeV (10⁹ eV), and TeV (10¹² eV).
Origin and History
The unit arose in the early 20th century as physicists studied electrons and ions accelerated in vacuum tubes and early particle accelerators, where energy expressed in volts of accelerating potential was far more natural than joules. It became the standard energy scale as quantum and nuclear physics matured.
Law and Notable Facts
The electronvolt is accepted for use with the SI system though it is not itself an SI unit. Via mass-energy equivalence, particle masses are routinely quoted in eV/c²: the electron's rest mass is about 511 keV/c², and the proton's is about 938 MeV/c².
Real-World Examples and Conversions
- Visible-light photons carry roughly 1.6 to 3.3 eV each.
- Chemical bond energies are typically a few eV per bond.
- The Large Hadron Collider accelerates protons to about 6.5 TeV, or 6.5 × 10¹² eV, roughly 1.04 microjoules per proton.
Frequently Asked Questions
How many electronvolts are in one erg?
One erg equals 6.24151 \times 10¹¹ eV, reflecting how tiny an electronvolt is compared with a CGS erg.
How do I convert electronvolts back to ergs?
Multiply the electronvolt value by 1.602177 \times 10⁻¹², so 1 eV = 1.602177 \times 10⁻¹² erg.
Why is the electronvolt count so large?
The electronvolt is an atomic-scale energy unit, so even the small erg contains hundreds of billions of them.
Where is this conversion used?
It appears in atomic, nuclear, and astrophysical work when energies measured or quoted in ergs must be expressed in the eV scale common to particle physics.
What is 100 ergs in electronvolts?
Multiply by the factor: 100 erg = 6.24151 \times 10¹³ eV.
People also convert
Complete Ergs conversion table
| Unit | Result |
|---|---|
| Watt-seconds (Ws) | 1e-7 Ws |
| Watt-minutes (Wm) | 1.666667e-9 Wm |
| Watt-hours (Wh) | 2.777778e-11 Wh |
| Milliwatt-hours (mWh) | 2.777778e-8 mWh |
| Kilowatt-hours (kWh) | 2.777778e-14 kWh |
| Megawatt-hours (MWh) | 2.777778e-17 MWh |
| Gigawatt-hours (GWh) | 2.777778e-20 GWh |
| Joules (J) | 1e-7 J |
| Kilojoules (kJ) | 1e-10 kJ |
| Megajoules (MJ) | 1e-13 MJ |
| Gigajoules (GJ) | 1e-16 GJ |
| British Thermal Units (IT) (BTU) | 9.478171e-11 BTU |
| US Therms (thm) | 9.480434e-16 thm |
| Electronvolts (eV) | 624150900000 eV |
| Foot-pounds (ft-lbf) | 7.375621e-8 ft-lbf |
| Tonnes of TNT (t-tnt) | 2.390057e-17 t-tnt |
| calories (cal) | 2.390057e-8 cal |
| Kilocalories (kcal) | 2.390057e-11 kcal |