Rhenium
Atomic symbol: R
Atomic number: 75
Atomic mass: 186.21
Appearance: Silver gray solid at 25°
Group: 7
Period: 6
Series: Transition metals
Block: d
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d⁵ 6s²
Dense and resistant to corrosion.
Fun Fact! Rhenium is one of the elements Mendeleev predicted existed when he first created the Periodic Table of Elements: he left a gap to be filled once rhenium had been discovered.