During change of O2 to O2- ion, the electron adds on which one of the following orbitals ?
- * orbital
- orbital
- * orbital
- orbital
Answer
(1) * orbital
Solution
O2 (16 electrons):
1s2 *1s2 2s2 *2s2 2pz2 ( 2px2 = 2py2) ( *2px1 = *2py1)
⇒ The highest occupied orbitals ( *2px, *2py) are half filled.
∴ In O2 + e- O2-, the added electron enters a * (antibonding) orbital:
O2-: ( *2px2 = *2py1)
Answer: (1)