What is the electron volt (EV) used to express?

What is the electron volt (EV) used to express?

• A. A unit of energy equal to 1.6 x 10^-19 joules.
• B. A unit of length.
• C. A unit of mass.
• D. A unit of power.

Answer: (A)

The electron volt is a unit of energy used for subatomic scales. It represents the energy gained by an electron when it is moved through a potential difference of one volt. Since the charge of an electron is about 1.602 x 10^-19 coulombs, this energy is E = qV = e × 1 V ≈ 1.6 x 10^-19 joules. This makes the electron volt convenient for describing energies of particles, photons, and binding energies in atomic and nuclear physics. It is not a unit of length, mass, or power, which is why those other options don’t apply.

The electron volt is a unit of energy used for subatomic scales. It represents the energy gained by an electron when it is moved through a potential difference of one volt. Since the charge of an electron is about 1.602 x 10^-19 coulombs, this energy is E = qV = e × 1 V ≈ 1.6 x 10^-19 joules. This makes the electron volt convenient for describing energies of particles, photons, and binding energies in atomic and nuclear physics. It is not a unit of length, mass, or power, which is why those other options don’t apply.