1 eV (electronvolt) in SI units is exactly 1.602176634 × 10-19 joules (J). This value is defined based on the elementary charge.
Understanding the Electronvolt (eV)
The electronvolt (eV) is a unit of energy commonly used in atomic and nuclear physics. It is defined as the amount of kinetic energy gained by a single electron when it accelerates through an electric potential difference of one volt.
The SI Value of 1 eV
According to the 2019 revision of the SI, the value of 1 eV is directly tied to the elementary charge (the charge of a single electron). Specifically, the numerical value of 1 eV in joules (J) is equal to the numerical value of the charge of an electron in coulombs (C). The accepted value is:
1 eV = 1.602176634 × 10-19 J
Table summarizing the information
| Quantity | Value | Unit |
|---|---|---|
| 1 eV | 1.602176634 × 10-19 | J |
| Elementary Charge | 1.602176634 × 10-19 | C |
Practical Implication
This precise value is essential for accurate calculations and measurements in fields like particle physics, solid-state physics, and chemistry where energies are often expressed in electronvolts due to the small scales involved.
