Select from the following molecular orbitals which are gerade ungerade
(a) `sigma(2s)` (b) `pi^(**)(2p_(x))` (c ) `pi ^(**)(2p_(y))`
(d) `sigma^(**)(1s)` (e) `pi (2p_(x))` (f) `pi (2p_(x))` .

Explanation

To determine which of the given molecular orbitals are gerade (G) and ungerade (U), we need to understand the definitions of these terms in the context of molecular orbital theory.

**Step 1: Understand the Definitions**
- **Gerade (G)**: These are molecular orbitals that remain unchanged in sign when the molecule is inverted through the center of symmetry. In simpler terms, if you rotate the orbital around its center, the phase (sign) of the wave function does not change.
- **Ungerade (U)**: These are molecular orbitals that change sign when the molecule is inverted through the center of symmetry. This means that the phase (sign) of the wave function does change upon rotation.

**Step 2: Analyze Each Molecular Orbital**
Now, we will analyze the given molecular orbitals one by one:
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