Whether hung on classroom walls, put up in dorm rooms or screen-printed on T-shirts, the periodic table of elements screams, “Science!” like no other image. And why not? At 118 members and counting, ...

This week's element is polonium, which has the symbol Po and the atomic number 84. Named in 1898 to help publicise Poland's lack of freedom at that time, polonium is the first element whose name was ...