I'm arguing with my almost 20-year-old son, to whom my 1980s college/varsity level education barely qualifies me to breathe unassisted (he has NO functional secondary education examination passes to shout about!)...

We were discussing an hypothetical 10km. cubed asteroid approaching on an Earth-impacting trajectory (Dinosaur-killer volume) after he was utterly poo-pooing the DART mission to Dimorphos.

I asked him how he would dispose of such a dinosaur-killing threat - to which he replied that it was simple(!). He'd dissolve it with the [sic] 'strongest acid & an air-gun delivery system'. Drops mic!!!

I'm unable to quantify the obstacles he'd face in attempting this, so, would the good folks here care to attempt to help me out with a coherent riposte?

I'd like to begin by discussing the methodology of 'asteroid vs. acid & air-guns' to begin, methinks. How a 1000km³ lump of asteroidal material at 4 Kelvin might be so destroyed on Earth itself?

Then, discuss how to package the calculated minimum amounts of these items, plus all failsafes required to launch them and just what would be required to escape Earth's gravity-well with all that on board. I suspect that arrangements for leaving Earth's orbit might be rather an afterthought here, nevertheless?

PS - I've no idea what he imagines would happen with the reaction products when they DO finally reach Earth!