Californium (atomic number = 98) is a member of

Options

A. s - block
B. p - block
C. d - block
D. f - block

Answer

To determine which block Californium (atomic number 98) belongs to, we need to analyze its electronic configuration step by step.

### Step 1: Determine the Electronic Configuration
To find the electronic configuration of Californium, we start from the lowest energy level and fill the orbitals according to the Aufbau principle. The order of filling is as follows:

- 1s²
- 2s²
- 2p⁶
- 3s²
- 3p⁶
- 4s²
- 3d¹⁰
- 4p⁶
- 5s²
- 4d¹⁰
- 5p⁶
- 6s²
- 4f¹⁴
- 5d¹⁰
- 6p⁶
- 7s²
- 5f¹⁰
- 6d¹⁰
- 7p⁶

### Step 2: Identify the Last Filled Orbital
For Californium (atomic number 98), we continue filling the orbitals until we reach the 98th electron. The electronic configuration can be summarized as:

\[ \text{[Rn]} \, 7s^2 \, 5f^{10} \, 6d^{0} \]

Here, the last filled orbital is 5f, which indicates that the outermost electrons are being filled in the f-block.

### Step 3: Determine the Block
Since the last filled orbital for Californium is 5f, we conclude that Californium belongs to the f-block of the periodic table.

### Conclusion
Therefore, Californium (atomic number 98) is a member of the f-block.

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