Talk:Elements/@comment-79.136.86.41-20141208192752/@comment-74.101.233.121-20150131024415

to get any of the numbered elements, you just have to do math. Simply combine 2 17s (Chlorine) to get selenium. To get chlorine, any 2 elements that add up to 17 will work. Same for Selenium; any 2 elements that add up to 34 will work.