The number of protons in an atom’s nucleus is equal to its atomic number?
The only cause we know of that could shift the spectrum of a source toward longer wavelengths isthe source moving away from us. That's how we interpret the red shift when we see it, and that's where the whole idea of the expanding universe comes from. But ... just like gravity and the Earth going around the sun ... it can't be proved, so it's "only a theory".
Answer : The energy for vacancy formation in silver is, 
Explanation :
Formula used :

or,

So,
![N_v=[\frac{N_A\times \rho}{M}]\times e^{(\frac{-E}{K\times T})}](https://tex.z-dn.net/?f=N_v%3D%5B%5Cfrac%7BN_A%5Ctimes%20%5Crho%7D%7BM%7D%5D%5Ctimes%20e%5E%7B%28%5Cfrac%7B-E%7D%7BK%5Ctimes%20T%7D%29%7D)
where,
= equilibrium number of vacancies = 
E = energy = ?
M = atomic weight = 107.9 g/mole
= Avogadro's number = 
= density = 
T = temperature = 
K = Boltzmann constant = 
Now put all the given values in the above formula, we get:
![3.6\times 10^{20}L^{-1}=[\frac{(6.022\times 10^{23}mol^{-1})\times 9500g/L}{107.9g/mol}]\times e^{[\frac{-E}{(1.38\times 10^{-23}J/K)\times 1073K}]}](https://tex.z-dn.net/?f=3.6%5Ctimes%2010%5E%7B20%7DL%5E%7B-1%7D%3D%5B%5Cfrac%7B%286.022%5Ctimes%2010%5E%7B23%7Dmol%5E%7B-1%7D%29%5Ctimes%209500g%2FL%7D%7B107.9g%2Fmol%7D%5D%5Ctimes%20e%5E%7B%5B%5Cfrac%7B-E%7D%7B%281.38%5Ctimes%2010%5E%7B-23%7DJ%2FK%29%5Ctimes%201073K%7D%5D%7D)

Therefore, the energy for vacancy formation in silver is, 
Answer:
4 moles CO₂ = 4 moles O₂
Explanation:
The incorrect mole ratio is 4 moles CO₂ = 4 moles O₂.
Let us write the reaction equation:
2C₂H₅OH + 7O₂ → 4CO₂ + 6H₂O
To write mole ratios in a chemical reaction, we must ensure the equation is balanced.
Since the given expression is balanced,
Then 4 moles CO₂ = 4 moles O₂ is not correct;
Rather;
4 moles CO₂ = 7 moles O₂ is the right expression