(a) Use orbital diagrams to illustrate what happens when an oxygen atom gains two electrons

Verified step by step guidance

1. Start by identifying the electron configuration of a neutral oxygen atom. Oxygen has an atomic number of 8, so its electron configuration is 1s^2 2s^2 2p^4.
2. Draw the orbital diagram for the neutral oxygen atom. The 1s and 2s orbitals are fully filled with two electrons each, and the 2p orbital has four electrons, which means two of the 2p orbitals are singly occupied, and one is doubly occupied.
3. When an oxygen atom gains two electrons, these electrons will fill the remaining empty spots in the 2p orbitals. This is because electrons fill orbitals in a way that minimizes energy, following Hund's rule and the Pauli exclusion principle.
4. Add the two additional electrons to the 2p orbitals in the orbital diagram. The 2p orbitals will now be fully filled with six electrons, resulting in a 2p^6 configuration.
5. The resulting electron configuration for the oxygen ion (O^2-) is 1s^2 2s^2 2p^6, which is the same as the electron configuration of neon, indicating a stable, noble gas configuration.

Key Concepts

Orbital Diagrams

Orbital diagrams are visual representations of the electron configuration of an atom, showing the distribution of electrons among the various atomic orbitals. Each orbital can hold a maximum of two electrons with opposite spins, and the diagrams help illustrate how electrons fill these orbitals according to the Aufbau principle, Hund's rule, and the Pauli exclusion principle.

Electron Configuration

Electron configuration describes the arrangement of electrons in an atom's orbitals. For oxygen, which has six electrons, the ground state configuration is 1s² 2s² 2p⁴. When an oxygen atom gains two electrons, it achieves a stable octet configuration, resulting in a new electron configuration of 1s² 2s² 2p⁶, similar to that of neon.

Ionic Charge and Stability

When an atom gains or loses electrons, it becomes an ion, which carries a positive or negative charge. In the case of oxygen gaining two electrons, it becomes an oxide ion (O²⁻), which is more stable due to achieving a full outer electron shell. This stability is a driving force behind the formation of ionic compounds, where atoms seek to attain a noble gas electron configuration.