I apologize for any confusion, but there are only four principal electron shells in an atom: the first shell (n = 1), the second shell (n = 2), the third shell (n = 3), and the fourth shell (n = 4). Each shell has a specific number of subshells and orbitals:
- The first shell (n = 1) contains only one subshell, which is an s subshell, and can hold a maximum of 2 electrons.
- The second shell (n = 2) contains two subshells: an s subshell (with 2 electrons) and a p subshell (with 6 electrons). Therefore, the second shell can hold a maximum of 8 electrons.
- The third shell (n = 3) contains three subshells: an s subshell (with 2 electrons), a p subshell (with 6 electrons), and a d subshell (with 10 electrons). So, the third shell can accommodate a maximum of 18 electrons.
- The fourth shell (n = 4) contains four subshells: an s subshell (with 2 electrons), a p subshell (with 6 electrons), a d subshell (with 10 electrons), and an f subshell (with 14 electrons). Consequently, the fourth shell can hold up to 32 electrons.
According to the information available, there is no fifth electron shell defined in the atomic structure as of 2023. If there have been recent advancements or discoveries in the field of atomic structure, I may not be aware of them.