The element californium belongs to a family of

Options

A. actinide series
B. alkali metals
C. alkaline earth metals
D. lanthanide series

Answer

To determine the family to which the element californium belongs, we can follow these steps:

### Step 1: Identify the Element
Californium is represented by the symbol **Cf** and has an atomic number of **98**.

### Step 2: Determine the Electronic Configuration
The electronic configuration of californium is given as:
- **Radon (Rn)** is the noble gas preceding californium.
- The electronic configuration can be written as: **Rn 5f^10 7s^2**.

### Step 3: Analyze the Electronic Configuration
In the electronic configuration:
- The last electron is filled in the **5f** subshell.
- This indicates that californium is an **f-block** element.

### Step 4: Classify f-block Elements
The f-block elements are divided into two series:
1. **Lanthanide series** (atomic numbers 57 to 71)
2. **Actinide series** (atomic numbers 89 to 103)

### Step 5: Determine the Series for Californium
Since californium has an atomic number of **98**, it falls between the atomic numbers of the actinide series (89 to 103). Therefore, californium belongs to the **actinide series**.

### Conclusion
Thus, californium belongs to the **actinide series**.

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