A gogen is a 5x5 grid made of the 25 letters of the alphabet A-Y (not Z). The across clues give you some of the letters to start. The down clues show words that can be made by moving from cell to cell in the grid to make the word (this includes diagonally). Think of it like Reverse Boggle. (The nice thing is you don’t have to know anything about chemistry, since I’ve already provided the words for you. And they’re not all themed anyway.)