Ionic compounds can conduct electricity when dissolved in water or melted, because

a. the ions are fixed in place.
b. they have shared electrons.
c. the ions are free to move.
d. they have no ions to contribute to the solution.

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.