Which term refers to the specific arrangement where an outer main energy level is filled with eight electrons?

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

Answer: (A)

Having a filled outer main energy level with eight electrons is called the noble-gas configuration. This follows the octet rule, where the valence shell is complete with eight electrons, producing a very stable, low-energy arrangement because all the available s and p orbitals in that shell are filled. Noble gases naturally exhibit this arrangement, which is why they’re generally inert, but the term that names the specific arrangement itself is noble-gas configuration. The other options describe broader ideas: noble gases refers to the elements that show this pattern, electron configuration is the general description of how electrons occupy orbitals, and chemical bonding refers to interactions between atoms to form compounds.