Electron Configuration Shortcut
Because writing the electron configuration can get really long, especially elements with atomic numbers in the one hundreds, there is an abbreviated way to write it. Looking at the picture above, the element is iron. Writing out the full configuration is long, so you can instead use the shortcut. To start the shortcut, find the noble gas from the previous energy level. After you have found that, start with the s sub level. The number that goes with the start corresponds with the row that the element you are writing the configuration for is on. Continue writing the configuration following the arrow diagram.