Question: what the most dangourus chemical

Stuart Atkinson answered on 5 Mar 2016:

Hi sparky. Good question. I’ll assume you mean dangerous in terms of toxicity, as chemicals can have other hazards too. If we’re talking about any material at all then it’s probably botulinum toxin which is lethal in nanograms (billionths of a gram). It’s bizarre that it’s the same thing that goes in botox injections. It works by paralysing nerves – not usually a good thing, but in tiny tiny amounts can take temporarily stop skin wrinkles caused by frowning.

In terms of chemicals that might be synthesised in a lab rather than extracted from natural materials, then cyanide is nasty (lethal in milligrams). Organic compounds of toxic metals are also highly dangerous, like methyl mercury.