Krypton has 8 valence electrons. What is true about krypton?

• A. Krypton is chemically inert and rarely forms compounds.
• B. Krypton is highly reactive with alkali metals.
• C. Krypton readily loses electrons to form positive ions.
• D. Krypton has a tendency to gain electrons to achieve a stable octet.

Answer: (A)

Verified step by step guidance

1. Identify the position of krypton in the periodic table. Krypton is a noble gas located in Group 18, which means it has a full valence shell with 8 valence electrons.
2. Understand the significance of having 8 valence electrons. Elements with a full octet are generally very stable and do not tend to gain or lose electrons easily.
3. Recall the chemical behavior of noble gases. Because their valence shells are full, noble gases like krypton are chemically inert and rarely form compounds under normal conditions.
4. Analyze the given options in light of krypton's electron configuration: it is unlikely to be highly reactive with alkali metals, lose electrons to form positive ions, or gain electrons to achieve stability, since it already has a stable octet.
5. Conclude that the correct statement is that krypton is chemically inert and rarely forms compounds due to its full valence shell.