* Parent Nuclide: Bromine-84 (⁸⁴Br)

* Daughter Nuclide: Krypton-84 (⁸⁴Kr)

* Process: A neutron within the bromine-84 nucleus transforms into a proton, emitting an electron (beta particle) and an antineutrino.

Here's the nuclear equation:

⁸⁴Br → ⁸⁴Kr + e⁻ + ν̄ₑ

Explanation:

* Beta particle (e⁻): The electron emitted during the decay is a beta particle.

* Antineutrino (ν̄ₑ): The antineutrino is an elementary particle with negligible mass that is also emitted to conserve energy and momentum.

* Atomic Number: The atomic number increases by one because a neutron becomes a proton. This changes the element from bromine (atomic number 35) to krypton (atomic number 36).

* Mass Number: The mass number remains the same because the total number of protons and neutrons in the nucleus doesn't change.

In summary:

Bromine-84 decays into krypton-84 through the emission of a beta particle and an antineutrino. This decay process results in a more stable nucleus with a higher atomic number.