What metallic element is sometimes used in flares and flashbulbs

Magnesium is used in flares and flashbulbs.

Explanation:

Magnesium is the metal having atomic number 12 and mass number 24

Magnesium burns with a brilliant white light and is used in pyrotechnics, flares and photographic flashbulbs.

Magnesium is the lightest metal that can be used to build things, although its use as a structural material is limited since it burns at relatively low temperatures.

Magnesium can be extracted from the minerals dolomite (CaCO3·MgCO3) and carnallite (KCl·MgCl2·6H2O), but is most often obtained from seawater.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.