A capital E is commonly used, e.g., Einstein's E=mc2
eg the qick brown fox jumped over the lazy fridge
The heaviest element with a one letter atomic symbol is uranium (symbol: U).
a letter or symbol that stands for one or more numbers is a
Energy does not have a symbol.
I don't think there is one but I'm not sure. I don't think you show energy on a symbol equation.
Potassium
The symbol for potential energy is U.
The symbol that is used to represent a joule is the letter "J". This is a derived unit of energy. It can also be used to represent work, and an amount of heat.
The energy unit is Joule for which the symbol is J. Imperial units for energy do not have the symbol W, either.
Chemical Symbol.
a variable
VARIABLE
It is a variable.