your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.
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Chemistry, 22.06.2019 02:20
6. what does the symbol ah stand for? o one calorie given off by a reaction the specific heat of a substance the heat capacity of a substance the heat of reaction for a chemical reaction
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.