State the Octet Rule and identify common exceptions.

• A. Eight electrons around main-group elements; exceptions include H (2), Be and B (less than octet), and elements beyond the second period that may have expanded octets.
• B. Eight electrons around main-group elements; exceptions are limited to noble gases.
• C. Two electrons around all atoms; this is always satisfied.
• D. Eight electrons around all atoms; always satisfied.

Answer: (A)

The octet rule states that atoms tend to have eight electrons in their valence shell to reach a stable, noble-gas-like configuration. This is most applicable to main-group elements, which achieve stability by gaining, losing, or sharing electrons to complete eight in their outer shell.

Common exceptions reflect real bonding patterns. Hydrogen is satisfied with two electrons in its only shell. Beryllium and boron often form stable species where the surrounding atoms give them only four or six valence electrons, not eight. Elements in the third period and beyond can have expanded octets, accommodating more than eight electrons around the central atom (for example, PF5 or SF6). Since these nuances exist, the description that mentions eight electrons with those specific exceptions best captures the typical rule and its deviations.