This group of elements contains brittle solids at room temperature. They are poor conductors (nonconductors) of heat and electricity.*
Metalloids
Non-Metals
Metals
None of the above

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.