A, B, C and D are four elements with atomic numbers Z - 1, Z, Z + 1 and Z + 2 respectively. B is a noble gas. Predict
whose hydroxide is less soluble in water.

Explanation

To solve the problem, we need to analyze the elements A, B, C, and D based on their atomic numbers and the information given about their groups in the periodic table.

### Step-by-Step Solution:

1. **Identify the Elements and Their Groups**:
- A has atomic number Z - 1.
- B has atomic number Z (given to be a noble gas).
- C has atomic number Z + 1.
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