What is the value of the elementary charge, e?

The elementary charge, denoted as ( e ), is a fundamental physical constant that represents the charge of a single proton (or the negative charge of a single electron) in units of coulombs. The accepted value of the elementary charge is approximately ( 1.602 \times 10^{-19} ) coulombs.

This value is critical in various fields of physics and electrical engineering as it underlies the quantization of charge, meaning that electric charges are typically found in integer multiples of this elementary charge. It plays a significant role in the equations of electromagnetism, atomic structure, and electrostatics, among other areas.

The other options provided do not represent the correct value of the elementary charge. For example, ( 9.109 \times 10^{-31} ) C refers to the mass of an electron rather than its charge. The value ( 1.000 \times 10^{-19} ) C is an incorrect approximation of the elementary charge, and ( 1.602 \times 10^{-18} ) C is simply ten times larger than the actual value, indicating a misunderstanding of the order of magnitude. Understanding the value and significance of the elementary charge is essential for anyone studying electrical