Approximately how many years has the atmospheric composition of Earth been roughly what it is today? a. 200 billion years b. 200 million years c. 4.5 billion years d. A few billion years

If a || b and e || f, what is the value of y ?

The first element on the periodic table of elements is carbon. a. true b. false

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.