The number of unpaired electrons present in palladium (Z=46) atom is

Options

A. 1
B. 2
C. Zero
D. 3

Answer

To determine the number of unpaired electrons in a palladium (Pd) atom, we will follow these steps:

### Step 1: Identify the Atomic Number
The atomic number of palladium (Pd) is 46. This indicates that a neutral palladium atom has 46 electrons.

### Step 2: Write the Electron Configuration
The electron configuration of palladium can be derived from the order of filling of the atomic orbitals. The noble gas preceding palladium is krypton (Kr), which has an atomic number of 36.

The electron configuration can be written as:
- Krypton (Kr): [Kr] = 36 electrons
- The next electrons fill the 4d and 5s orbitals:
- 4d can hold a maximum of 10 electrons.
- 5s can hold a maximum of 2 electrons.

Thus, the electron configuration of palladium is:
\[ \text{Pd: [Kr] 4d}^{10} 5s^{0} \]

### Step 3: Analyze the Electron Configuration
From the electron configuration:
- The 4d subshell has 10 electrons.
- The 5s subshell has 0 electrons.

### Step 4: Determine the Number of Unpaired Electrons
To find the number of unpaired electrons, we need to look at the distribution of electrons in the d orbitals:
- The 4d subshell has 10 electrons, which means all the d orbitals (dxy, dyz, dxz, dx2-y2, dz2) are fully filled.

Since all the electrons in the 4d subshell are paired, there are no unpaired electrons.

### Conclusion
The number of unpaired electrons in a palladium atom is **0**.

### Final Answer
The number of unpaired electrons present in palladium (Z=46) atom is **0**.

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