F block elements are known as

Options

A. transition elements
B. inner transition elements
C. intransitiin elements
D. outer transition elements

Answer

**Step-by-Step Solution:**

1. **Understanding F-Block Elements:**
- F-Block elements are those elements where the last electron enters the f-orbital. These elements are found in the two rows at the bottom of the periodic table.

2. **Identification of the Energy Level:**
- The f-block elements correspond to the filling of the 4f and 5f orbitals. This means that the last electron added to these elements is in the 4f or 5f subshell.

3. **Penultimate Energy Level:**
- The term "anti-penultimate" refers to the energy level that is one level below the outermost shell. In the case of f-block elements, the outermost shell is the 6th or 7th shell, and the anti-penultimate shell is the 4th or 5th shell, where the f-orbitals are located.

4. **Inner Transition Elements:**
- Because the f-block elements involve the filling of inner orbitals (4f and 5f), they are also referred to as "inner transition elements." This distinguishes them from the s- and p-block elements, which are considered outer transition elements.

5. **Conclusion:**
- Therefore, F-Block elements are known as "inner transition elements" due to their unique electron configuration and the fact that their valence electrons enter the anti-penultimate energy level.

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