Answer:
Yes it can, but it will be rather radioactive.
Step-by-step explanation:
Each element has a distinctive number of protons, neutrons, and electrons. Gold, for example, has 79 protons (its atomic number), 118 neutrons, and 79 electrons (if in its neutral form). To change one element to another, the number of protons needs to be altered.
Since platinum and mercury have similar nucleus compositions when compared with gold, repeatedly subjecting platinum or mercury nuclei to neutron bombardment could knock off or add on a neutron, eventually creating gold.
Needless to say, it's probably easier to just go mining for gold.