Only 25 Elements are needed for mammalian life:
Lets say by bad luck that a planet had only these 25 elements and none of the others were present at all anywhere in the planets crust / surface. Intelligent life evolves, what level of technology can they get to? Steam age seems like its no problem, nuclear fission is out but maybe they can eventually develop fusion?
Can they develop computers? modern medicine? launch rockets into orbit? can they eventually develop any kind of nuclear tech to create the “missing elements” they don’t have?