Final answer:
An electric kettle with the heating element at the top will not work effectively due to the inefficient transfer of heat to the water because convection currents cannot be established properly to heat the water evenly.
Step-by-step explanation:
An electric kettle with the heating element at the top will not work effectively because of the way heat is transferred in liquids through a process called convection. Convection occurs when the warmer, less dense fluid rises, while the colder, denser fluid sinks. If the heating element is at the bottom, it heats the water from below, causing the warm water to rise and the cooler water to circulate down, creating a convection current that evenly heats the entire body of water. However, if the heating element is at the top, the heat does not effectively reach the colder water at the bottom, making the heating process very inefficient. In an electric kettle, this inefficient heating means that the water will take a longer time to boil, if it boils at all.