Question

19. Explain Aufbau principle and write the order of energies of the orbital.​

Answer 1

Answer:

According to the Aufbau principle, electrons first occupy those orbitals whose energy is the lowest. ... The order in which the orbitals are filled with electrons is: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, and so on

Answer 2

According to Aufbau principle, the electron are filled in various orbitals in order of their increasing energies.

for the order, hope the image below helps.

if its a textual question then my ans is competent

but if you want an explanation of concept,

check out physics wallah's vid on YouTube about this principle.

its 100% gonna help