True, it is formed from immense weathering over time. Hope it helped!
        
             
        
        
        
I think its mass of volume 
 
        
             
        
        
        
Because the alkali metals are the group 1 metals, they have only 1 valence electron that they want to lose, and the halogens are the group 17 nonmetals, they want to gain 1 valence electron to become stable.
        
                    
             
        
        
        
I think they test ideas about chemical evolution by doing experiments. Hope this helps
        
                    
             
        
        
        
Answer:
 Calculating Atomic Mass
Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass.
Explanation:
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