Which of the following metals is extracted in the middle of the activity series?

The correct option is Iron.

Understanding the Activity Series of Metals:
The activity series (or reactivity series) is an arrangement of metals in decreasing order of their chemical reactivity. Based on their position in this series, metals are generally categorized into three groups for extraction purposes:

1. Metals of High Reactivity (Top of the Series):
Metals such as Potassium (K), Sodium (Na), Calcium (Ca), Magnesium (Mg), and Aluminium (Al) are placed at the top of the reactivity series. Because they are highly reactive, they are never found in nature in a free state and are extracted by the process of electrolysis of their molten ores.

2. Metals of Medium Reactivity (Middle of the Series):
Metals such as Zinc (Zn), Iron (Fe), Lead (Pb), and Copper (Cu) are moderately reactive and lie in the middle of the activity series. These metals usually exist as sulfides, carbonates, or oxides in nature. They are extracted by roasting or calcination followed by reduction using reducing agents like carbon (coke).

3. Metals of Low Reactivity (Bottom of the Series):
Metals such as Gold (Au), Silver (Ag), and Platinum (Pt) are at the bottom of the activity series. They are least reactive and often found in their free (native) state in nature.

Analyzing the Given Options:

• Gold (Au): Found at the bottom of the reactivity series (unreactive/least reactive).

• Potassium (K): Found at the top of the reactivity series (highly reactive).

• Sodium (Na): Found at the top of the reactivity series (highly reactive).

• Iron (Fe): Found in the middle of the reactivity series (moderately reactive).

Therefore, Iron is the metal extracted in the middle of the activity series.