Some isotopes, however, decay slowly, and several of these are used as geologic clocks. Dating rocks by these radioactive timekeepers is simple in theory, but the laboratory procedures are complex. <span>All methods rely on the fact that certain elements (particularly uranium and potassium) contain a number of different isotopes whose half-life is exactly known and therefore the relative concentrations of these isotopes within a rock or mineral can measure the age.</span>
        
             
        
        
        
They are formed by natural processes like anærobic decomposition. They contain energy from ancient photosynthesis. They can literally be around 650 million years old.
        
                    
             
        
        
        
Answer:
The correct answer is - economic, social, environmental, and geopolitical 
Explanation:
Natural Resources are the resources that are formed in nature on their own and can be renewable or non-renewable. There are various risks and benefits are associated with the production of all forms of energy other resource extraction.
These costs or risk includes economic, environmental, social, and geopolitical risks. These risks have various factors that decide if these risk or benefit and can be altered by the new technologies using for the extraction and production of various forms of energy.
 
        
             
        
        
        
Answer:
The growth factor receptors have a kinase domain while the Cytokines receptors do not contain a kinase domain as part of their structure.
Explanation:
The two are signaling molecules that control cell activities in some manners, such paracrine, endocrine and autocrine manners.
The receptor kinase domain can be specific for substrate sites in which phosphorylation occurs.