The symbol that represents enthalpy is:
ΔH
Enthalpy is defined as the heat absorbed or released by a system at constant pressure, and it is represented by the symbol ΔH (delta H). The symbol Δ (delta) indicates a change in the quantity that follows, which in this case is H (enthalpy). So, ΔH represents the change in enthalpy of a system during a chemical or physical process.