Chicxulub impact estimated 300 ZJ, zetta being 10^21 giving us 10^23 and 10^-10. Avogadro's constant is 6×10^23.

So that's 10^33 protons or 5/3×10^9 moles. It's difficult to get a sense of what that actually means because protons aren't a typical substance. I guess the closest human relatable approximation might be liquid hydrogen. That's about 2 g/mol and ~0.71 g/ml so 2.82 ml/mol but that's H2 (ie 2 protons) so our equivalent would be 1.41 ml/mol yielding 2.35 million liters.

I tried to compare to oil tankers but glancing at Wikipedia it seems the smallest crude tankers are at least 25× that size. The largest oil tankers in the world (of which there are 4) carry ~450 million liters which works out to ~191 chicxulub equivalents (assuming I did all the math correctly).

According to Wikipedia Castle Bravo was ~500 L of lithium deuteride and yielded ~63 PJ making it ~5 million of those to 1 chicxulub equivalent; the supertanker would equate to about 1 billion. In other words ~1000× more energy density than lithium deuteride powered fusion which is itself already so absurd that it's difficult to comprehend.

That was a lot more involved than I expected. I really hope I didn't misplace an order of magnitude or three anywhere.