Final answer:
The basic SI unit of enthalpy, energy, or heat is described as the joule (J). This unit is defined by the energy expenditure when a 1 newton force moves an object over a distance of 1 meter. Historically, the calorie was used but has since been standardized to 4.184 joules.
Step-by-step explanation:
The term used to describe the basic SI unit of enthalpy, energy, or heat is joule (J). The joule is defined as the amount of energy used when a force of 1 newton moves an object 1 meter, and is equivalent to 1 kilogram meter squared per second squared (1 kg m²/s²) or 1 newton-meter.
While energy was historically measured in calories, with one calorie being the energy required to raise one gram of water by 1 degree C, the SI unit for energy is now the joule. Since 1 calorie had variability depending on atmospheric pressure and the starting temperature, it has been standardized to equal exactly 4.184 joules.