>>14113982No and no.
Actual scientists make their rules from their observations, not their observations from their rules.
We don't "predict" what a new compound will do, let alone what a new element would do. We study the properties of the compounds after we make them.
The closest we come to prediction is when there are probability distributions of different properties depending on how the elements or compound arrange themselves en mass due to conditional changes in their formation. This is how predictive software works for proteins and such. But remember: there is no prediction on how a compound will form that doesn't come from observations of different formations and applications of statistics, and there are no properties that are predicted by the combinations, only actual experiments that then reveal the property.
As for isotopes, they react chemically the same as normal, but have a different mass, and can affect the energy in the system, creating different properties for the same reaction or the same compound.
There is also the inconvenience that most isotopes decay, changing the compound, and of course giving off neutrons, which are dangerous.
