The electronic configuration of an element 'X' is 2,8,8,2. Write its (i) group number, (ii) period number and (iii) the number of valence electrons in its atom. Justify your answer in each case.

Explanation

To solve the question regarding the element 'X' with the electronic configuration of 2, 8, 8, 2, we will determine its group number, period number, and the number of valence electrons.

### Step-by-Step Solution:

1. **Identify the Period Number:**
- The electronic configuration is given as 2, 8, 8, 2. The number of shells corresponds to the number of energy levels or periods.
- The last number in the configuration (2) indicates that there are four energy levels (or shells) in total.
- Therefore, the period number for element 'X' is **4**.
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