Final answer:
The mystery metal has a density of 3 g/mL, which is greater than the density of water (1 g/mL), indicating it will sink in water.
Step-by-step explanation:
To calculate the density of a substance, we use the formula where p stands for density, m for mass, and V for volume. In the provided scenario, a piece of metal with a volume of 20 mL and a mass of 60 grams has a density calculated as follows:
Density (p) = Mass (m) / Volume (V)
Density = 60 g / 20 mL = 3 g/mL
A substance with a density greater than water, which has a density of 1 g/mL, will sink in water. Since the metal's density is 3 g/mL, it is denser than water, so it will sink.