Nuclear charge of an element B is twice that of A. If A has two completely filled orbits and L shell is its outermost orbit, find out atomic numbers of A and B.

Explanation

To solve the question, we need to determine the atomic numbers of elements A and B based on the information provided.

### Step-by-Step Solution:

1. **Understanding Nuclear Charge**:
- The nuclear charge of an element is determined by the number of protons in its nucleus.
- Let the nuclear charge (or number of protons) of element A be represented as \( Z_A \).
- According to the question, the nuclear charge of element B is twice that of A, so we can express this as:
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