How many electrons can the 5th shell hold? 8 18 24 32 50

Each shell contains a fixed number of electrons. The general formula of the number of electrons can be hold in n-th shell is 2n². 5th shell can hold 2x5² = 50  number of electrons.

1st shell contains 2 X 1²= 2 number of electrons, 2nd shell contains 2 X 2²=8 number of electrons, 3rd shell contains 2 X 3²=18 number of electrons, 4th shell contains 2 X 4²=32 number of electrons,  5th shell contains 2 X 5²=50 number of electrons and so on.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be