441.

Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region?

• Balmer series

• Paschen series

• Brackett series

• Lyman series

Non - directional orbital is :

• 4p

• 4d

• 4f

• 3s

Assertion (A) : Atoms with completely filled and half-filled sub-shells are stable.

Reason (R): Completely filled and half-filled sub-shells have symmetrical distribution of electrons and have maximum exchange energy.

The correct answer is

• (A) and (R) are correct, (R) is the correct explanation of (A)

• (A) and (R) are correct, (R) is not the correct explanation of (A)

• (A) is correct, but (R)is not correct

• (A) is not correct, but (R) is correct