The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

At its most stable atomic weight of 258, it is considered one of the 'superheavy'-weights of the periodic table. Like most of the heavier elements, it's so large that it has trouble sticking itself ...

But the story of element 87 begins much earlier than its discovery date in 1939. When Mendeleev first proposed his periodic table in 1869 he left gaps for elements not yet discovered, but that he ...