Question

an atom of a certain element contains 9 protons and 7 valence electrons. a student studying this element is trying to determine the identity of the element, as well as the reactivity. which answer correctly identifies the element?
the element is nitrogen (n) and it is highly reactive.
the element is fluorine (f) and it is highly reactive.
the element is nitrogen (n) and it is not reactive.
the element is fluorine (f) and it is not reactive.
part b
which of the following statements best supports your answer to part a?
valence electrons are used to identify elements and the 9 protons make the element highly reactive.
protons are used to identify elements and the 7 valence electrons make the element not reactive.
valence electrons are used to identify elements and the 9 protons make the element not reactive.
protons are used to identify elements and the 7 valence electrons make the element highly reactive.

Explanation:

In Part A, the number of protons determines the identity of an element. An element with 9 protons is fluorine. Fluorine has 7 valence electrons and is highly reactive as it only needs to gain 1 electron to achieve a stable octet. In Part B, protons are used to identify elements, and having 7 valence electrons makes an element highly reactive as it is close to achieving a stable electron - configuration by gaining an electron.

Answer:

Part A: The element is fluorine (F) and it is highly reactive.
Part B: Protons are used to identify elements and the 7 valence electrons make the element highly reactive.