Question

The maximum no. of electrons in the third main energy level, 20y orbital and 3 d sub shell are respectively………………………..

• 9, 6, 9
• 18,6,10
• 9,2,5
• 18,2,10

Answer 1

you posted a question about d electrons in the organic section lol

More importantly, what is "20y", it's not a notation i've seen. You can narrow down your options since the 3d subshell can hold a maximum of 10 electrons, it can only be 1 of these:

18,6,10
18,2,10