Final answer:
The valence shell electron configuration of noble gases except for helium is ns2np6, which represents a full outer shell conforming to the octet rule, making these elements stable and unreactive.
Step-by-step explanation:
The valence shell electron configuration of all the noble gases except for helium is ns2np6. The noble gases have a full outer shell of electrons, which means they have eight valence electrons except for helium, which only has two. This full set of eight valence electrons, aligning with the octet rule, makes the noble gases very stable and unreactive. An example of this is neon (Ne), which has an electron configuration of 1s²2s²2p⁶, representing a complete valence shell.