A crystalline solid dissolves in water, conducts electricity when it is dissolved, and has a melting point of 670 degrees Celsius.

A) pure element
b) ionic compound
c) covalent compound

gravity causes stares to cluster i think so

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.