In general density is represented by the Greek symbol rho (ρ)
In lower classes viz sixth standard, the first letter of the word "density" ie 'd' is used. But later in higher studies instead 'd', 'rho' the greek letter is used as the symbol for density.
The energy spectral density describes how the energy (or variance) of a signal or a time series is distributed with frequency.You can read more in Wikipedia 'Spectral Density', but you will need good maths to understand it!
If you refer to the unit, the international unit for energy is the joule; the symbol is "J".
The Greek letter "rho" (looks like a lower case p) usually stands for density.
In general density is represented by the Greek symbol rho (ρ)
Energy does not have a symbol.
the density of cesium is 1.93 and its atomic # is 55 symbol Cs
Density is the lower case greek letter rho.
The energy unit is Joule for which the symbol is J. Imperial units for energy do not have the symbol W, either.
The symbol for Sempra Energy in the NYSE is: SRE.
Energy density is the amount of power that can be stored ( in for example capacitance) to be then consumed over time, whereas power density is how much energy is consumed quickly like the energy stored in a capacitance can be consumed very quickly.
'Cu' is the chemical symbol for copper. The density of copper is 8.96 gm/cm3 .
In lower classes viz sixth standard, the first letter of the word "density" ie 'd' is used. But later in higher studies instead 'd', 'rho' the greek letter is used as the symbol for density.
The symbol for CAMAC Energy Inc. in the AMEX is: CAK.
The symbol for Dejour Energy Inc. in the AMEX is: DEJ.
The symbol for Energy Fuels Inc in the AMEX is: UUUU.