These flashbacks to his dad always make me tear up. As Senku finds more and more pieces of platinum in the gold dust we get to see how his dad spent his whole life gathering them.
I'd never heard of a silent bomb, but that's a pretty novel idea, whoever came up with it. That the reaction of plaster forming as it expands would be strong enough to break concrete.
As for the nitric acid machine, I feel they skipped over a little too much in how he even made that machine. Unless he already had it prepared in his kit and was just waiting for the platinum to slot in. But also how did he make that platinum coil? It has a melting point of 1772°C, so that can't possibly be fused together with the tools he had.
Still, I'm pretty excited to see the gang get back together for the 2nd cour and take down this villain.