II SEP Construct an Explanation Air-activated hand warmers consist
of an iron powder contained in a porous pouch. When the pouch is
removed from its air-tight packaging, oxygen from the air enters the
pouch and reacts with the iron to produce iron(III) oxide. Construct
an explanation for why the pouch gets hot based on changes in
total bond energy.

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. the change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. the minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kj/mol.