Answer:
Can you translate it on English so we can understand
 
        
             
        
        
        
 The atom that would gain two electrons to fill its valence energy level is S(sulfur)
This is because s (sulfur) is in atomic number 16 with 2.8.6 of [Ne] 3s^2 2p^4 electronic configuration. This implies that sulfur has 6 valence electron and therefore it require two electron to fill its valence energy level and obtain 18 rule electrons.
 
        
                    
             
        
        
        
The atoms  of  hydrogen  that are  present  in  7.63 g  of ammonia(NH3)
find  the  moles  of NH3 =mass/molar mass
 7.63 g/ 17 g/mol = 0.449  moles
since there  is  3 atoms of H  in NH3 the  moles of  H = 0.449 x 3 = 1.347 moles
by  use  of  1 mole = 6.02 x10^23  atoms
what  about  1.347  moles
= 1.347  moles/1   moles  x 6.02 x10^23 atoms = 8.11 x10^23  atoms of Hydrogen
        
             
        
        
        
Answer: Observation is essential in science. Scientists use observation to collect and record data, which enables them to construct and then test theories 
Explanation: