Answer:
A. when dissolved in water
Explanation:
Water is an extremely polar molecule, meaning it has a positive end a negative end. When an ionic compound is dissolved, the positive pole of water will be attracted to the negative ion and attach itself to it. The same goes for the positive ions. That's how water breaks down ionic compounds
All I can say is that Mercury is a liquid at room temperature, and liquids will very slowly evaporate at room temperature. This is because the molecules have a relatively low energy at room temperature (since room temperature is very low compared to boiling point). The boiling point of mercury is 356.73 degrees Celsius, and room temperature is only about 23 degrees Celsius, so the evaporation rate at room temperature would be little to nothing.
