When a ligand forms a closed ring with the metal atom, the complex formed is called ……. .

Explanation

To answer the question, "When a ligand forms a closed ring with the metal atom, the complex formed is called …….," we can follow these steps:

### Step 1: Understand the Concept of Ligands
Ligands are ions or molecules that can donate a pair of electrons to a metal atom to form a coordination complex. They can be classified based on the number of donor atoms they possess.

**Hint:** Remember that ligands can be unidentate (one donor atom), bidentate (two donor atoms), or polydentate (multiple donor atoms).

### Step 2: Identify the Type of Ligands Involved
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