What do you mean by 1 eV?

What do you mean by 1 eV? A common physics unit in atomic and particle physics, “electron volt” represents a specific amount of energy gained by an electron accelerated through an electric potential difference of 1 volt.

Definition of 1 eV

An electron volt (eV) is the amount of kinetic energy acquired (or work done on) an electron when it is accelerated through a potential difference of 1 volt. It is a very small energy unit used in atomic and nuclear physics.

Formula and Meaning

By definition:
1 eV = 1 electron × 1 volt.
Since 1 volt = 1 joule per coulomb and electron charge ≈ 1.602×10⁻¹⁹ C, we get:

1 eV ≈ 1.602 × 10⁻¹⁹ joules (J)

Physical Interpretation

When an electron is moved through a potential difference (electric field) of 1 volt, the energy it gains or loses is exactly 1 eV. This makes eV a convenient unit in microscopic energy scales like atomic binding energy, photon energy, and particle collisions.

Note: The electron volt is not a unit of electric potential — it is a unit of energy, particularly useful in atomic, molecular, and particle physics.