Question

which is responsible for a spoon left in a coffee cup becoming hot to touch? conduction radiation convection

Explanation:

Conduction is the transfer of heat through direct contact. In this case, the hot coffee is in direct contact with the spoon, transferring heat energy to the spoon via conduction. Radiation is heat transfer through electromagnetic waves and convection is heat transfer through the movement of fluids (like air or liquid in bulk motion). Since the heat transfer here is due to direct - contact between the coffee and the spoon, it's conduction.

Answer:

Conduction