In a certain γ decay process, an excited neon atom emits a γ-ray that has an energy of 2.853 MeV.  The neon atom in the ground state has a mass of 19.992 435 u.  What is the mass of the excited neon atom?    

 

20.498 658 u     

 

20.002262 u     

 

19.994118 u     

 

19.999 685 u     

 

20.003 185 u