Question

A science teacher set up a fish tank in her classroom to bring science to life. While cleaning the fish tank, a small piece of a plant broke away from the stem and floated upward and in the opposite direction of the heater. Upon reaching the opposite end of the tank, the plant piece gradually sank. It then floated back to the heater, where it rose once again. This movement repeated until the plant piece was removed from the fish tank.

As water cools, it becomes more dense. As water reached the surface of the tank, it became cooler and began to sink. As the water sank, it heated again and moved upward again.
The plant piece cycled around the tank with the moving water. This cycling of cool and warm water is an example of
A. convection.
B. conduction.
C. expansion.
D. radiation.

Answer 1

The cycling movement of the plant piece is caused by convection, where warm water rises and cool water sinks, creating a cycle that moved the plant around the tank.

Step-by-step explanation:

The movement of the plant piece in the fish tank can be explained by the process of convection. This is because the warmer water from the heater expands, becomes less dense, and rises, while the cooler water becomes denser and sinks. This process not only moved the plant piece around the tank but also facilitates the transfer of heat within the fish tank's water. In the context of geology, natural convection is responsible for driving plate tectonics, significantly impacting the Earth's surface over geological timescales, similar to the effect on the moving water in the classroom fish tank.