Question

question 18
which of the following is chemically inert (unreactive)?
○ sodium (atomic number 11)
○ carbon (atomic number 6)
○ neon (atomic number 10)
○ oxygen (atomic number 8)

Explanation:

Chemically inert elements are typically noble gases, which have a full valence electron shell. Neon (atomic number 10) is a noble gas with an electron configuration of \(1s^2 2s^2 2p^6\), meaning its outermost shell is full. Sodium (atomic number 11) is a metal with one valence electron, so it is reactive. Carbon (atomic number 6) has four valence electrons and is reactive, forming many compounds. Oxygen (atomic number 8) has six valence electrons and is reactive, participating in many chemical reactions (e.g., combustion, respiration). So neon is chemically inert.

Answer:

C. neon (atomic number 10)