Answer:
The<u> heat transfer </u>model showed convection.
In the convection model, the red water on the bottom of the beaker <u>is hot</u>
This means that the water at the bottom of the beaker was <u> less dense than </u>the water near the top of the beaker.
Explanation:
<em>Convection</em> is the transference of heat energy by the movement (translation) of the particles of fluid (liquids or gases).
When the water on the bottom of the beaker is heated, it expands and becomes less dense.
The water near the top of the beaker is cold which makes it denser than the water at the bottom of the beaker.
Thus, the hot water from the bottom of the beaker will ascend toward the top of the beaker, while the cold water on top will descend toward the bottom. As long, as there is a difference of temperature between the water on the bottom and on top of the beaker, there will be a continuous movement of the particles: cold particles from the top replace hot particles from the bottom that ascend, and when the cold particles are heated they will ascend and will be replaced by new cold particles. This continuous translation of hot and cold particles in fluids is the model of heat transfer by convection.
