Convection is the transfer of heat energy in a gas or liquid by movement of currents. The heat moves with the fluid. The movement of a gas, liquid, or solid as a result of the random thermal motion of it atoms or molecules. For instance, a drop of food coloring in water will slowly spread throughout the water. Blood will diffuse through the ocean and attract sharks.
Energy is defined as the ability to do work.
If you push on a car and it doesn't move, you have done no work. Evaporation is when a liquid changes state to the gaseous state. This occurs at the surface of the liquid when random molecules escape from the surface of the liquid. As evaporation occurs, the liquid cools. A force of 1 newton will accelerate a MASS of 1 kilogram to a speed of 1 meter per second in 1 second.