Answer: Carbon can form single, double, and triple bonds is a characteristic of a typical carbon atom.Carbon is one of the most abundant and essential chemical elements on earth. Carbon has an atomic number of 6 and does not dissolve in water. Carbon is nonmetallic and tetravalent (has four valence electrons). Carbon atoms have the ability to form single, double, and triple covalent bonds with other atoms. Carbon atoms can bond together in various ways (allotropes) and they include graphite, diamond, and amorphous carbon.  
Explanation:
 
        
                    
             
        
        
        
Elephant poaching is an example
        
             
        
        
        
Independent variable: is the UV light exposure 
Control group: people not exposed (sample b)
Dependent variable: skin cancer
Experimental group: (sample A)
        
                    
             
        
        
        
A shadow is a surface light cannot touch or reflect off of. Usually shadows appear when the main object is covering a light source. For example, lunar eclipses. Lunar eclipses cause a shadow over Earth because they block the main light source, The Sun from our point of view, casting a giant shadow over Earth.