Question

What role does heat play in the formation of convection currents?

A. When water loses heat, it becomes denser and sinks
B. When water gains heat, it becomes denser and sinks
C. When water loses heat to cooler water, the cooler water becomes denser and sinks
D. When water gains heat, it dissolves more solids and gases, becomes denser, and sinks

Answer 1

Heat causes fluids to expand and become less dense, leading to the rise of the warmer portions and the sinking of cooler, denser portions, thus creating convection currents. Therefore, the correct option is a.

Step-by-step explanation:

The role of heat in the formation of convection currents is the driving force that creates movement within fluids such as water or air. When a fluid such as water gains heat, it expands, decreases in density, and rises because it becomes lighter than its surroundings. This process is described in choice A: 'When water loses heat, it becomes denser and sinks.' Meanwhile, cooler water that loses heat becomes denser and sinks to replace the warmer rising water, setting up a cycle known as a convection current.