What are inner-transition elements? Decide which of the following atomic number are the numbers of the inner transition elements: `29,59,74,95,102,104`

Explanation

### Step-by-Step Solution:

1. **Definition of Inner Transition Elements**:
- Inner transition elements are those elements in which electrons are added to the f subshell. This typically occurs in the two series of elements known as lanthanoids and actinoids.

2. **Identifying the Series**:
- The lanthanoids (or lanthanides) are the elements with atomic numbers 58 to 71.
- The actinoids (or actinides) are the elements with atomic numbers 90 to 103.
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