Based on the activity series of metals, which of the following elements is most reactive with oxygen?

• A. Silver (Ag)
• B. Copper (Cu)
• C. Gold (Au)
• D. Potassium (K)

Answer: (D)

Verified step by step guidance

1. Understand that the activity series of metals ranks metals based on their reactivity, especially their tendency to lose electrons and form positive ions.
2. Recall that metals higher in the activity series react more vigorously with oxygen, forming oxides more readily.
3. Identify the metals given: Silver (Ag), Copper (Cu), Gold (Au), and Potassium (K). Note that Potassium (K) is not listed among the first three but is mentioned as the correct answer.
4. Recognize that Potassium (K) is an alkali metal located near the top of the activity series, meaning it is highly reactive with oxygen compared to the transition metals Silver, Copper, and Gold, which are much less reactive.
5. Conclude that among the given options, Potassium (K) is the most reactive with oxygen because it is higher in the activity series and more readily forms oxides.