Question

in 1807 the English chemist Humphrey Davy passed an electric current through molten potassium hydroxide and isolated a bright, shiny reactive substance. He claimed the discovery of a new element, which he names potassium. In those days, before the advent of modern instruments, what was the basis on which one could claim that a substance was an element.

Answer 1

Characteristic metallic properties similar in character to sodium (couldn’t be broken down further).