Which of the following is a lanthanide ?

Options

A. Ta
B. Rh
C. Th
D. Lu

Answer

To determine which of the given options is a lanthanide, we need to analyze each option based on their atomic numbers and their classification in the periodic table.

**Step 1: Identify the options provided.**
The options given are:
1. Tantalum (Ta)
2. Rhodium (Rh)
3. Thorium (Th)
4. Lutetium (Lu)

**Step 2: Check the atomic numbers and classification of each element.**
- **Tantalum (Ta)**:
- Atomic number: 73
- Classification: D-block element (Transition metal)

- **Rhodium (Rh)**:
- Atomic number: 45
- Classification: D-block element (Transition metal)

- **Thorium (Th)**:
- Atomic number: 90
- Classification: Actinide (F-block element)

- **Lutetium (Lu)**:
- Atomic number: 71
- Classification: F-block element (Lanthanide)

**Step 3: Identify which element is a lanthanide.**
- Lanthanides are elements with atomic numbers from 57 (Lanthanum) to 71 (Lutetium).
- Among the options, Lutetium (Lu) with atomic number 71 falls within this range.

**Conclusion:**
The lanthanide from the options provided is **Lutetium (Lu)**.

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