What is the electron ring formation for iron

Good Morning, Ali. Iron has the following electron structure: 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d6. Or, using shorthand it would be [Ar] 4s2, 3d6 as the Noble Gas Argon has the configuration of the first 5 orbitals I listed above. The shorthand method is preferred as there is less chance of writing one of the orbitals in the incorrect sequence.
Any good Chemistry textbook or Periodic Table will have this information included.