Question

An accelerated electron has an energy of 6.4 × 10⁻¹⁹ J. Express the energy of electron in electron volts (eV).

Answer 1

1.6 × 10⁻¹⁹ J = 1 eV

\[ \therefore\ 6.4 \times 10^{-19}\ \mathrm{J} = \frac{1 \times 6.4 \times 10^{-19}}{1.6 \times 10^{-19}}\] = 4 eV