What element exhibits the most similar reactivity to chlorine, and what are the reasons for this similarity?

Question

A. Fluorine because at room temperature they are both gases
B. Fluorine because they both have seven valence electrons
C. Phosphorus because they are both located in the same period
D. Oxygen because they both gain two electrons to form anions

Answer 1

The element that exhibits the most similar reactivity to chlorine is:

B. Fluorine because they both have seven valence electrons.

Reasons for this similarity:

1. Similar Valence Electrons: Both chlorine and fluorine are halogens, and they both have seven valence electrons in their outer shell. This configuration makes them highly reactive as they strive to gain one additional electron to achieve a full outer electron shell (octet), which is the most stable arrangement.

2. Reactivity in the Same Group: Chlorine and fluorine are in the same group (Group 17, the halogens) of the periodic table, meaning they share similar chemical properties and reactivity patterns. Elements in the same group tend to have similar behaviors in chemical reactions.

Options A, C, and D do not accurately describe the reasons for chlorine's reactivity in terms of similarity with other elements:

• A is incorrect since while both are gases at room temperature, reactivity is more strongly influenced by electron configuration.
• C is incorrect because phosphorus is in a different group and does not share the same reactivity profile as chlorine.
• D is incorrect because although oxygen can gain electrons, it gains two to form anions, whereas chlorine gains one. Therefore, oxygen’s reactivity is quite different from that of chlorine.