Capitolo Chimica

Trasformazioni della materia, energia e ambiente

Chemistry in English

Glossary

Law of conservation of energy: Energy can be converted from one form to another, but the total energy of a system and its surroundings remains constant.
Kinetic energy: Energy possessed by an object in motion.
Thermal energy: A form of energy associated with the motion of particles (atoms, molecules, ions) constituting a body.
Heat: Thermal energy flowing between two bodies at different temperatures.
Chemical energy: The potential energy associated with the electrical interactions between atoms, ions and molecules in a body.
Reaction heat: The amount of heat released or absorbed in a chemical reaction.
Endothermic reactions: Chemical reactions in which the system converts thermal energy into chemical energy. More generally, in endothermic reactions energy is absorbed from the surroundings and at the end of the reaction the system possesses more energy than at the start.
Exothermic reactions: Chemical reactions in which thermal energy (heat) flows out into the surroundings. More generally, in these kinds of processes energy is transferred to the surroundings and at the end of the reaction the system possesses less energy than at the start.
Specific heat (or specific heat capacity): The amount of heat absorbed (or released) by 1 kg of material when its temperature increases (or decreases) by 1 °C.
Heating power: Amount of heat obtained from the perfect combustion of 1 kg or 1 m³ of combustible material.
Enthalpy (H): Thermodynamic quantity associated with every substance. In exothermic transformations the enthalpy of a system decreases while it increases in endothermic ones.
Fossil fuels: Fuels containing high percentages of carbon, including coal, petroleum and natural gas.
Non-renewable or exhaustible energy sources: Naturally occurring substances of which there is a finite supply: such as fossil fuels and uranium minerals.