Astatine has 85 electrons, arranged 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p5. Written on the previous noble gas that is [Xe] 4f14 5d10 6s2 6p5, and the shells hold 2, 8, 18, 32, 18, 7 electrons from the innermost outwards.
Hund's rule leaves 1 unpaired electron in the ground state, which is what makes the free atom paramagnetic.
The periodic table, read every way a chemistry course asks for. This tool needs JavaScript; these are the pages it offers: