Question

1. choose the best answer. why are noble gases the least reactive nonmetal group? they have 7 valence electrons. they have 7 electrons. they have 8 valence electrons. they have 8 electrons. 4) choose the best answer. noble gases are ____. monatomic inert and monatomic radioactive inert

Explanation:

• For the first question: Noble gases are stable because they have a full valence shell. A full valence shell for most noble gases (except helium which has 2) is 8 valence electrons. Having 7 valence electrons (like halogens) makes them reactive as they want to gain one more. Just having 7 or 8 electrons (not specifying valence) is incorrect as it's about the out - most shell electrons.
• For the second question: Noble gases are inert (unreactive) due to their full valence shells. They are also monatomic (exist as single atoms). While some noble gases can be radioactive (e.g., radon), not all are. Saying just "inert" or "monatomic" is incomplete as they have both properties.

Answer:

1. They have 8 valence electrons.
2. inert and monatomic