Introduction to Physical Science/Energy
Many Forms of Energy 
By 9th grade (U.S. system) some students can identify potential energy (energy stored in objects due to their position - snow on a steep slope) and kinetic energy (displayed by snow when it breaks loose and an avalanche falls down the steep slope.) Some students recognize the heat is a form of energy as well. In fact, depending on the context of the discussion, students may identify many forms of energy, such as: Potential, Kinetic, Thermal, Chemical, Electrical, Magnetic, Sound, Nuclear and so on.