To determine the total number of inner transition elements from the given list of elements (W, Ru, U, Tc, La, Yb, Po, No), we need to identify which of these elements are classified as inner transition elements. Inner transition elements consist of the lanthanides and actinides.
### Step-by-Step Solution:
1. **Identify Inner Transition Elements**:
- Inner transition elements are the lanthanides (elements 57-71) and actinides (elements 89-103) in the periodic table.
2. **Analyze Each Element**:
- **W (Tungsten)**: Not an inner transition element (it is a transition metal).
- **Ru (Ruthenium)**: Not an inner transition element (it is a transition metal).
- **U (Uranium)**: Yes, Uranium is an actinide and thus an inner transition element.
- **Tc (Technetium)**: Not an inner transition element (it is a transition metal).
- **La (Lanthanum)**: While Lanthanum itself is not typically classified as an inner transition element, it is the first element of the lanthanide series. However, it is often included in discussions about inner transition elements.
- **Yb (Ytterbium)**: Yes, Ytterbium is a lanthanide and thus an inner transition element.
- **Po (Polonium)**: Not an inner transition element (it is a post-transition metal).
- **No (Nobelium)**: Yes, Nobelium is an actinide and thus an inner transition element.
3. **Count the Inner Transition Elements**:
- From the analysis, the inner transition elements identified are:
- U (Uranium)
- Yb (Ytterbium)
- No (Nobelium)
- If we include La (Lanthanum) as part of the inner transition elements, we have four elements.
- However, typically, we count only the lanthanides and actinides that are not the first in their series, leading us to count U, Yb, and No.
4. **Final Count**:
- The total number of inner transition elements from the given list is 3 (U, Yb, No).
### Final Answer:
The total number of inner transition elements from the given list is **3**.
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