Would alpha decay taste sour? If someone were foolish and/or brave enough to build a device to focus the alpha decay products from a radioactive sample, then point it at their tongue through their open mouth, would it taste sour, assuming there were sufficient helium nuclei?
On one hand, I can imagine the eletro-negativity of the alpha decay products being high enough that it would act as an acid and trigger the sour-response in the taste bud. 
On the other hand, I can imagine it not tasting like anything for the two following reasons:


*

*The helium nucleus might quickly gain electrons and become inert before it 
had a chance to trigger a neural response

*The helium nucleus might cause enough damage to the taste buds to render them ineffective
I know this is a bit of a silly question, but what would alpha-decay taste like?
 A: You are likely thinking of protons having a sour taste, since we experience H$^{+}$ as sour (actually, it is H$_3$O$^+$ in water). However, alpha particles either zip through the sensory cells and just act as ionizing radiation or slow down and then behave like tasteless helium. 
Apparently ionizing radiation does produce a metallic taste when it is strong enough, perhaps due to breaking down lipids. There may be an ozone smell too. A strong alpha source might achieve that. 
(There may be other effects too. Depletion of some types of taste sensory cells is likely: radiation therapy commonly affects taste acuity. Charged particles can trigger neural firing too.)
I am more curious about the taste of a proton beam. It might be sour, but most likely just acts as intense ionizing radiation. Anatoli Bugorski did experience it as brightness, but it did not pass through his mouth as far as I know.
A: No. As pointed out by Jon Custer in comments, an alpha particle is not a proton. It's a helium nucleus, and helium is chemically unreactive, so it has no taste.
