Question

15 a student observes that element x has a completely filled outer valence electron shell
predict one physical or chemical property element x would exhibit, and justify your prediction using your knowledge of atomic structure and chemical reactivity.
review the information carefully. then enter your answer and your explanation in the box provided.

Explanation:

• Physical/Chemical Property: Low reactivity (inertness).
• Justification: Elements with completely filled outer valence electron shells (like noble gases) have a stable electron configuration. According to the octet rule (for main - group elements, having 8 electrons in the valence shell is stable), they do not easily gain, lose, or share electrons. Since chemical reactivity is related to the tendency of atoms to achieve a more stable electron configuration (usually by filling the valence shell), a completely filled valence shell makes the element less likely to participate in chemical reactions.

Answer:

Element X would likely be unreactive (chemically inert). This is because a completely filled outer valence electron shell gives it a stable electron configuration. Atoms tend to react to achieve a stable electron configuration (usually a full valence shell). Since it already has a full valence shell, it has little tendency to gain, lose, or share electrons, making it unreactive.