Polonium has an atomic number of 84 in the periodic table and is solid at 20 degrees Celsius. It is an alpha emitter which is used to extract a thin film for stainless steel. They are used for antistatic devices and a good source of heat for space machines. The correct electron configuration of a polonium atom is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p4. What is lacking in his configuration is the presence of the f sub shell. He should have added 4f14 before 5d10 because if he did not add it, it would give another element.