Answer:
Group VII has the most reactive elements
 
        
             
        
        
        
<span>Begin by classifying which energy level, and indirectly principal quantum number, n, resembles to the N shell.
no. of orbitals =n2
In your case, the fourth energy level will contain
n=4⇒no. of orbitals= 4^2=16
The number of subshells is given by the principal quantum number.
no. of subshells=n
In your case, the fourth energy level will have
no. of subshells = 4 this is the answer
to check:
the fourth energy shell will can hold a thoroughgoing of no. of electrons=2⋅42=32 e−</span>
        
                    
             
        
        
        
Answer:
Hey
It should be Atomic theory,
First proposed in the 15th centery by Aristotle, it states that all matter is made of <em><u>induvisable particles called atoms...</u></em>
 
        
             
        
        
        
The reaction is as follows:
2 H₂(g) + O₂(g) → 2 H₂O(g) . ΔH = - 483.5 kJ
Using the change in enthalpy and heat, calculate the moles as follows:
Moles of H₂ = - 

 x 2 mol H₂
                  = - 216 kJ / (-483.5 kJ) x 2 mol H₂ 
                  = 0.893 mol H₂
Calculate the mass of H₂ using the moles and molar mass as follows:
0.893 mol H₂ x (2.02 g H₂ / 1 mol H₂) = 1.79 g H₂
Therefore, the mass of hydrogen gas is 1.79 g
 
        
        
        
Answer:
I believe the answer would be C4H9O2.