Answer: -
6
Explanation: -
The given unbalanced chemical equation is As + NaOH -- > Na3AsO3 + H2
We see there 3 sodium on the right side from Na3AsO3.
But there are only 1 sodium on the left from NaOH.
So we multiply NaOH by 3.
As + 3 NaOH -- > Na3AsO3 + H2
Now we see the number of Hydrogen on the left is 3.
But the number of hydrogens is 2 on the left.
So, we multiply to get both sides 6 hydrogen.
As + 6NaOH -- > Na3AsO3 + 3 H2
Rebalancing for Na,
As + 6NaOH -- > 2Na3AsO3 + 3 H2.
Finally balancing As,
2 As + 6 NaOH -- > 2Na3AsO3 + 3H2
The coefficient of the NaOH molecule in the balanced reaction is thus 6
 
        
             
        
        
        
Answer: D:wavelenght
Explanation: Students will understand that shorter wavelengths have higher frequency and energy. 
 
        
                    
             
        
        
        
It showed that the nucleus is positively charged, and that the atom isn't just made of electrons.
        
             
        
        
        
The equation presented above is that of uranium reacting with fluorine forming uranium fluoride. 
The chemical reaction can be balanced by carefully studying the equation and balancing the number of atoms of each of the element in both sides of the chemical reaction. That is,
 
                  <em>         U(s) + 3F₂(g) --> UF₆(g)</em>
        
                    
             
        
        
        
Answer:
12 grams of hydrogen gas
and 56 grams of nitrogen gas
The molar mass of ammonia is 17 g/mol.
68 grams of ammonia corresponds to  
17g/mol
68g
 =4moles
4 moles of ammonia will be obtained from  
2
4×1
 =2  moles of nitrogen and  
2
4×3
 =6  moles of hydrogen.
The molar masses of nitrogen and hydrogen are 28 g/mol and 2 g/mol respectively.
2 moles of nitrogen corresponds to 2×28=56  grams.
6 moles of hydrogen corresponds to 6×2=12  grams.