The world of superheroes has some pretty cool stuff: green rocks that make a sun god weak, a magic hammer that channels lightning, and robots that walk, talk, and transform. But how are you supposed to keep track of all that stuff? We've got you covered. Check out our Periodic Table of Superhero Elements, which tells you where an element comes from, what it does, and its notable uses in the world of superheroes, sci-fi, and beyond. Joshua is IGN’s Comics Editor.