* Increased Kinetic Energy: The molecules within the liquid absorb the heat energy and start moving faster. This increased kinetic energy causes them to vibrate and collide more frequently.

* Expansion: As the molecules move faster, they push further apart, causing the liquid to expand in volume. This is why you might see a liquid rise in a container when heated.

* Change in Density: The expansion leads to a decrease in the liquid's density, as the same mass now occupies a larger volume.

* Increased Vapor Pressure: The increased molecular motion also leads to more molecules escaping from the liquid's surface into the surrounding air, increasing the vapor pressure.

* Change in Viscosity: The viscosity of a liquid (its resistance to flow) often decreases as it is heated. Think of honey - it flows much more readily when warm.

* Boiling Point: If you continue to heat the liquid, eventually it will reach its boiling point. At this temperature, the vapor pressure equals the surrounding atmospheric pressure, and the liquid begins to change into a gas.

Important Note: The specific effects of heating will depend on the type of liquid and the temperature it's heated to. Some liquids might evaporate before reaching their boiling point, while others might decompose or undergo chemical reactions.