Answer
5.0 mL of that solution.
Work Step by Step
1. Identify the equalities and conversion factors that we will use to solve this problem:
$$0.10 \space mg=1 \space mL \space of \space solution$$
2. Solve the problem using this conversion factor:
$$0.50 \space mg \times \frac{1 \space mL \space of \space solution}{0.10 \space mg} = 5.0 \space mL \space of solution$$
