For every category, you must name the five elements that have jumbled, minus a letter. When you unscramble an element, the missing letter will appear by its name. Once all five elements in a category have been named, unscramble the missing letters to get the final element for that category. Note that there is one letter missing in that jumble as well. Once all five categories are complete, unscramble the missing letters in the final category elements to get the final element (with a missing letter).