What is the approximate ratio of the mass of proton and electron?

Electrons and Protons:

1. Electrons are negatively charged particles.
2. Protons are positively charged particles.

$$\begin{gathered} \text{Mass of proton}=1.6\times {10}^{-27}\mathrm{kg} \\ \text{Mass of electron}=9.1\times {10}^{-31}\mathrm{kg} \\ \therefore \frac{\text{Mass of proton}}{\text{Mass of electron}}=\frac{1.6\times {10}^{-27}}{9.1\times {10}^{-31}} \\ =1.8\times {10}^3 \end{gathered}$$

Hence, the approximate ratio of the mass of proton and electron is $1.8\times {10}^3$.