Answer
Mg=220 pm
Zn=130 pm
the atomic radius difference is larger than 15
They do not satisfy the above condition so it is not complete solubility.
Work Step by Step
For a substitutional solid solution having complete solubility, the following conditions must be satisfied:
1. Atomic radius difference must be less than 15.
2. Both have same electronegativity.
3. Both have same crystal structure.
4.Both have same valence electrons.
Mg=220 pm
Zn=130 pm
the atomic radius difference is much larger than 15
