Question

When a $4\mathrm{p}$ orbital is completely filled then the next electron goes to _______-

Answer 1

1. Aufbau Principle: According to the Aufbau principle, the electrons are occupied in the orbitals in the order of increasing energy.
2. The order of filling up of orbitals is as follows: $1\mathrm{s},2\mathrm{s},2\mathrm{p},3\mathrm{s},3\mathrm{p},4\mathrm{s},3\mathrm{d},4\mathrm{p},5\mathrm{s},4\mathrm{d},5\mathrm{p},6\mathrm{s}.....$
3. Orbital next in energy to 4p is 5s..
4. Therefore when a $4\mathrm{p}$ orbital is completely filled then the next electron goes to the $5\mathrm{s}$ orbital.