Electron configuration is an organized assignment of the electrons of a particular atom in the periodic table. It is the distribution of electrons of an atom or a molecule in orbitals. For platinum (Pt), its atomic number is 78 which mean that there are 78 electrons to be distributed. The organization of the orbitals is as follows:
`1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^2 5s^6 4d^10 5p^6 6s^2 4f^14 5d^10 6p^6 (and so on)`
There are mnemonics to follow for the organizations of the orbitals. Now for platinum, we have to distribute the 78 electrons. We count the superscripts of the orbitals (e.g. `2p^6` = 6 electrons)
The final electronic configuration for platinum would be:
`1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^2 5s^6 4d^10 5p^6 6s^2 4f^14 5d^8`
In some books, the configuration of atoms may vary because electrons have tendencies to jump to other orbitals. In case of platinum, one electron in 6s orbitals can jump to the 5d orbitals making the last three orbitals to be `6s^1 4f^14 5d^9` .