Complex compounds of transition metals are familier, but not inner transition elements. Why?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Terms:**
- Transition metals refer to the d-block elements in the periodic table, while inner transition elements refer to the f-block elements.

2. **Properties of Transition Metals:**
- Transition metals possess empty d orbitals. This characteristic allows them to form complex compounds easily.
- Their ions are generally small and highly charged, which contributes to the stability of the complexes they form.
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