The First Blank Is Chemical And The Last Blank Is Potential.
        
             
        
        
        
Explanation:
    Isotopes: 
                           ₁₅³¹P   and     ₁₅³²P
      Given parameters: 
         ₁₅³¹P                                                   ₁₅³²P            
    Mass number = 31                                    32
    Atomic number = 15                                 15
The two atoms are isotopes. Now let us derive numbers of their subatomic particles 
                        ₁₅³¹P                                             ₁₅³²P   
Protons              15                                                 15
Electrons           15                                                  15
Neutrons         (31-15) = 16                               (32-15) = 17
Because they are isotopes, they differ in the number of neutrons alone. 
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences  in the number of their neutrons. 
We clearly see that the mass number and number of neutrons pertaining to the atom differs. This makes them isotopes. 
Learn more: 
Isotope brainly.com/question/1915462
#learnwithBrianly
 
        
             
        
        
        
Decaying uranium atoms in the earth's crust result in Radon gas. Radon gas cannot be synthetically or commercially produced.  It is produced as the result of the natural breakdown of uranium i.e. decaying uranium atoms. Radon gas is a naturally occurring radioactive gas. People are exposed to Radon gas via the inhalation and ingestion of the gas. Because it is found in the ground, water or building materials, Radon gas can enter work buildings as well as private dwellings. 
        
             
        
        
        
Answer:
Hitched a ride or Humans brought it and planted it.
Explanation: