Final answer:
Based on the given specific heat value and silver/gray appearance, the metal in question is likely to be lead.
Step-by-step explanation:
The question is about identifying a metal based on its mass in water and air, along with its specific heat and appearance.
The specific heat value given, Cmetal = 0.13 J/g °C, is similar to that of either gold (Au) or lead (Pb). However, gold is not silver/gray, whereas lead is. Thus, the presence of a silver/gray color in addition to the given specific heat value suggests that the metal is lead.
It's also important to consider density in such comparisons. If you had equal-sized samples of aluminum and gold, the density difference would be immediately noticeable due to the substantial difference in mass, with gold being much denser and heavier.
For gold, the density is approximately 19 g/cm³, and for a metal to be identified as gold, it should have a visual appearance consistent with gold and a density close to the value mentioned. In the case of lead, color and specific heat are more indicative.