Ching Man struggled to understand how energy is stored in fuel-oxygen systems and how two
changes can be coupled. There is no evidence that he understood the symbolism of the arrows of
spontaneity, and whereas he attempted some explanations for what happens to water when it is
heated, is left to cool, is electrolysed and is formed when hydrogen and oxygen react, in a later
activity he matched the changes a bath of hot water cools down and a person uses up food running
a race to the same abstract picture showing energy escaping through cooling. It is worth noticing,
however, that in the activity just mentioned he matched the cooling and warming changes correctly
and from the chemical changes the only one that could be thought as more familiar to him, wood
burning.