Kryptonite is a fictional substance from the Superman radio showcomic books). The word kryptonite is used in speech to describe someone's or something's weakness. The material, usually shown as having been created from the remains of Superman's native planet of Krypton, generally has detrimental effects on Superman. The name "kryptonite" covers a variety of forms of the substance, but usually refers to the most common series (and subsequent related media, most notably the "green" form.
1. What is "green form"?
2 kryptonite =[SIZE=-1]Achilles' heel? according to above explanation which I excerpted from Wikipedia[/SIZE]