Why are the noble gases the least reactive elements? (1 point)
A They have a full valence electron shell.
B They have an empty inner electron shell.
C They are the most electronegative elements.
D They are the elements with the smallest atomic mass.
A They have a full valence electron shell.
The correct answer is A) They have a full valence electron shell. Noble gases, such as helium, neon, and argon, have a full valence electron shell, meaning that their outermost energy level is completely filled with electrons. This stability makes noble gases very unreactive and unlikely to form chemical bonds with other elements.
The correct answer is A: They have a full valence electron shell.
To explain why noble gases are the least reactive elements, we need to understand the concept of valence electrons. Valence electrons are the electrons in the outermost shell of an atom. They are responsible for the chemical behavior and reactivity of an element.
Noble gases, also known as Group 18 elements, have a special electron configuration. They have a full valence electron shell consisting of 8 electrons, except for helium which has only 2. This makes them very stable and unreactive. The tendency of atoms to acquire, lose, or share electrons is driven by the desire to achieve a stable electron configuration.
Since noble gases already have a stable electron configuration, they do not easily gain, lose, or share electrons with other elements. This stability is due to the fact that they have a complete octet, which means their valence shell is fully filled. As a result, noble gases generally do not form chemical bonds with other elements and are considered to be inert or unreactive.
To summarize, noble gases are the least reactive elements because they have a full valence electron shell, which provides them with stability and prevents them from readily participating in chemical reactions.