Elementary Charge (e): The Fundamental Unit of Electric Charge | changeunit.com
The elementary charge (e) is a fundamental physical constant and the smallest unit of electric charge that can exist freely. It is the magnitude of the charge of a single proton or electron. By convention, a proton has a charge of +e, and an electron has a charge of -e. This concept is a cornerstone of physics, as it confirms that electric charge is quantized—it exists only in discrete, indivisible units.
While the coulomb (C) is the SI unit of charge, it is simply a large collection of elementary charges. The value of the elementary charge is defined precisely and is a critical constant in all of science. ⚛️
The Value of Elementary Charge (e)
The accepted value of the elementary charge is approximately:
e ≈ 1.602 x 10-19 C
This incredibly small number highlights why a coulomb is considered such a large unit of charge. It would take over six quintillion elementary charges to make up just one coulomb of charge. The precise measurement of this value was a landmark achievement in physics, most famously determined by Robert Millikan in his 1909 oil drop experiment. [Image of Robert Millikan's oil drop experiment]
Why is it "Elementary"?
The name "elementary" signifies that this is the most basic, fundamental amount of charge. While subatomic particles called quarks have fractional charges (e.g., +2/3 e or -1/3 e), they cannot be isolated and observed individually. Quarks only exist in groups, and their combined charge is always a whole-number multiple of the elementary charge, e. This means that any observable object, from an atom to a planet, will have a total charge that is a perfect integer multiple of e.
Elementary Charge Conversion Table
On changeunit.com, you can easily convert between elementary charge and other common units of charge. Here is a helpful reference table showing the relationships between e and other units:
| Unit | Symbol | Conversion Factor to Elementary Charge (e) |
|---|---|---|
| Elementary Charge | e | 1 e |
| Coulomb | C | 1 C ≈ 6.242 x 1018 e |
| Millicoulomb | mC | 1 mC ≈ 6.242 x 1015 e |
| Microcoulomb | µC | 1 µC ≈ 6.242 x 1012 e |
| Nanocoulomb | nC | 1 nC ≈ 6.242 x 109 e |
| Picocoulomb | pC | 1 pC ≈ 6.242 x 106 e |
| Franklin | Fr (statC) | 1 Fr ≈ 2.081 x 109 e |
The elementary charge is the fundamental building block of all electrical phenomena. Understanding this tiny, constant value is key to grasping the nature of matter and electricity itself. Visit changeunit.com to explore more conversions. ⚡️