The metal spoon is hotter than the wooden spoon due to its higher mass,
Heat is the energy transferred from one body to another due to a temperature difference. The amount of heat transferred is proportional to the mass of the object and its specific heat capacity. Specific heat capacity is the amount of heat required to raise the temperature of one unit mass of the substance by one degree Celsius.
In this scenario, the two spoons are of equal size, but the metal spoon has a higher mass and specific heat capacity compared to the wooden spoon. When both spoons are placed in the boiling water, heat flows from the water to the spoons until they reach the same temperature as the water.
However, due to the higher mass and specific heat capacity of the metal spoon, it requires more heat energy to raise its temperature compared to the wooden spoon. As a result, the metal spoon takes a longer time to reach the same temperature as the wooden spoon.
Additionally, metals are better conductors of heat compared to wood. Therefore, the metal spoon conducts the heat more efficiently from the boiling water to the handle, making it hotter than the wooden spoon.
Overall, the metal spoon is hotter than the wooden spoon due to its higher mass, higher specific heat capacity, and better heat conduction properties. This is why it would be more painful to grab.