Bohr model of an atom illustrates a nucleus with electrons circling around it. This is a useful model for understanding atoms because this clarified that atoms are actually composed of three particles: protons, neutrons and electrons. The first two are located at the center part of an atom (nucleus), while electrons are located at the outer part. Valence electrons of an atom are also vital in the creation of different chemical compounds.
Answer:
Explanation:
Molar heat capacity at constant volume Cv of a gas = n x .5 R where n is degree of freedom of the gas molecules
CO₂ is a linear molecule , so number of degree of freedom = 3 + 2 = 5
3 is translational and 2 is rotational degree of freedom . There is no vibrational degree of freedom given .
So Cv = 5 / 2 R
= 2.5 R .
If you change the subscripts it would change the reactants or products and then you would be solving a different formula, you would change what the chemical is
Answer : All of the above are valid expressions of the reaction rate.
Explanation :
The given rate of reaction is,

The expression for rate of reaction for the reactant :
![\text{Rate of disappearance of }NH_3=-\frac{1}{4}\times \frac{d[NH_3]}{dt}](https://tex.z-dn.net/?f=%5Ctext%7BRate%20of%20disappearance%20of%20%7DNH_3%3D-%5Cfrac%7B1%7D%7B4%7D%5Ctimes%20%5Cfrac%7Bd%5BNH_3%5D%7D%7Bdt%7D)
![\text{Rate of disappearance of }O_2=-\frac{1}{7}\times \frac{d[O_2]}{dt}](https://tex.z-dn.net/?f=%5Ctext%7BRate%20of%20disappearance%20of%20%7DO_2%3D-%5Cfrac%7B1%7D%7B7%7D%5Ctimes%20%5Cfrac%7Bd%5BO_2%5D%7D%7Bdt%7D)
The expression for rate of reaction for the product :
![\text{Rate of formation of }NO_2=+\frac{1}{4}\times \frac{d[NO_2]}{dt}](https://tex.z-dn.net/?f=%5Ctext%7BRate%20of%20formation%20of%20%7DNO_2%3D%2B%5Cfrac%7B1%7D%7B4%7D%5Ctimes%20%5Cfrac%7Bd%5BNO_2%5D%7D%7Bdt%7D)
![\text{Rate of formation of }H_2O=+\frac{1}{6}\times \frac{d[H_2O]}{dt}](https://tex.z-dn.net/?f=%5Ctext%7BRate%20of%20formation%20of%20%7DH_2O%3D%2B%5Cfrac%7B1%7D%7B6%7D%5Ctimes%20%5Cfrac%7Bd%5BH_2O%5D%7D%7Bdt%7D)
From this we conclude that, all the options are correct.