The following metal shows ferromagnetic nature

Options

A. Co
B. `Cr^(+3)`
C. `Ni^(+2)`
D. `Cu^(+1)`

Answer

To determine which of the given metals exhibit ferromagnetic nature, we will analyze each metal one by one.

### Step 1: Understand Ferromagnetism
Ferromagnetism is a property of certain materials where the magnetic moments of atoms align in the same direction, resulting in a strong magnetic field. Common ferromagnetic materials include iron, cobalt, and nickel.

**Hint:** Remember that ferromagnetic materials have unpaired electrons that contribute to their magnetic properties.

### Step 2: Analyze Each Metal
1. **Cobalt (Co)**: Cobalt is a well-known ferromagnetic material. It has unpaired electrons that align in a magnetic field, making it ferromagnetic.

**Hint:** Look for elements in the d-block that are known for their magnetic properties.

2. **Chromium (Cr) +3**: Chromium in its +3 oxidation state does not exhibit ferromagnetism. While chromium itself has some magnetic properties, it is not ferromagnetic in this oxidation state.

**Hint:** Consider the oxidation states of metals and how they affect magnetic properties.

3. **Nickel (Ni) +2**: Nickel is another metal that exhibits ferromagnetic properties. In its +2 oxidation state, nickel retains its ferromagnetic characteristics.

**Hint:** Check if the metal is in a stable oxidation state that supports ferromagnetism.

4. **Copper (Cu) +1**: Copper is not ferromagnetic. It is diamagnetic due to its fully filled d-orbitals in the +1 oxidation state.

**Hint:** Remember that fully filled d-orbitals typically lead to diamagnetism.

### Step 3: Conclusion
From the analysis, the metals that show ferromagnetic nature from the given options are:
- **Cobalt (Co)**
- **Nickel (Ni)**

**Final Answer:** Cobalt and Nickel show ferromagnetic nature.