a radioactive element decays to bromine-81 after electron capture. what is the chemical symbol for the nuclide that forms

The nuclear reaction depicting electron capture decay is: X + e- --> z-1Y + ve. The electron on the left side of the equation is usually absorbed from the K or L shell of the parent nucleus. Note the reduction in atomic number but conservation of mass number in the daughter nucleus.

Explanation:

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.