Final answer:
The Beta negative decay of gold-198 results in the emission of a beta-minus particle and a neutrino, with the gold nucleus transforming into a mercury nucleus as one neutron becomes a proton.
Step-by-step explanation:
The Beta negative decay of gold-198 involves a neutron within the gold nucleus converting into a proton. During this process, an electron (known as a beta particle or beta-minus particle) and a neutrino are emitted to conserve total electric charge. Since the mass number (A) remains unchanged and the atomic number (Z) increases by one, the gold nucleus moves to a different element on the periodic table, specifically mercury (Hg). As gold-198 undergoes beta-minus decay, it essentially 'moves' one place to the left (N decreases by one) and one place up (Z increases by one) on the chart of nuclides.