# To what does energy belong in an energy diagram?

Does the energy belong to the system or to the outside?

• I mean "the system" (~reactants) – Marouane RASSILI Mar 18 '15 at 10:49
• What "energy" are you referring to here? – Kyle Kanos Mar 18 '15 at 12:56
• The energy mentioned in the vertical Axis. – Marouane RASSILI Mar 18 '15 at 13:23
• That bar represents the direction of an increase in energy, much the same way the axis lines for an $x$-$y$ plot. – Kyle Kanos Mar 18 '15 at 13:30
• it represents the energy change of the reactants to its final state, no? – Marouane RASSILI Mar 18 '15 at 13:38