a student heats a liquid on a burner. what happens to the portion of liquid that first begins to warm?\nit…

Brief Explanations:

When a liquid is heated, its molecules gain kinetic energy and move more vigorously, spreading apart. This causes the volume of the heated - portion of the liquid to increase while the mass remains the same. According to the density formula $\rho=\frac{m}{V}$ (where $\rho$ is density, $m$ is mass, and $V$ is volume), an increase in volume with constant mass results in a decrease in density.

Answer:

It becomes less dense.