An outer main energy level occupied by eight electrons is an example of

• A. Noble-gas configuration
• B. Noble gases
• C. Electron configuration
• D. Chemical bonding

Answer: (A)

Having eight electrons in the outermost shell means the valence shell is full, a stable arrangement that mirrors the electron structure of noble gases. This specific full-shell configuration is called a noble-gas configuration. Atoms strive to reach this octet because a complete valence shell is especially stable, which is why elements tend to gain, lose, or share electrons to achieve it. It’s not just any electron configuration; it’s the particular full-shell arrangement that characterizes noble gases. Bonding can help reach this state, but the label here refers to the electron count in the outer shell, not the act of bonding itself.