Answer:
b) 1s2 2s2 2p6 3s2 3p6 4s2 4d8
Step-by-step explanation:
Electron configuration of an atom is given based on the Aufbau principle which states that electrons are arranged in orbitals such that the lower energy orbitals are filled first. The increasing energy order of orbitals is:
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p....
s, p ,d orbitals can accommodate a maximum of 2,6 and 8 electrons respectively.
Based on the above ordering, the most reasonable ground state configuration would be:
1s2 2s2 2p6 3s2 3p6 4s2 4d8