I think it’s B vibrations in molecules
Explanation: The Kinetic Theory of Matter states that matter is composed of a large number of small particles—individual atoms or molecules—that are in constant motion.
The kinetic energy of an object increases when heat is added.
<h3>Al + O2 -> Al2O3</h3>
Balance it:
<h3>2Al + 3O2 -> 2Al2O3</h3><h3 />
So you need 2 Al and 3 O2 to make 2 Al2O3 (aluminum oxide).
I'm going to assume you have all the O2 you need.
Since 2 mols of Al is needed to make 2 mols of the product, it's a 1:1 ratio. You get as much aluminum oxide for as much aluminum you burn.
So 12.5 mols if there is not a lack of the O2.
<span>The </span>standard enthalpy of formation<span> <span>is defined as the change in </span></span>enthalpy<span> <span>when one mole of a substance in the </span></span>standard<span> <span>state (1 atm of pressure and temperature of 298.15
K) is </span></span>formed<span> <span>from its
pure elements under the same conditions.</span></span>
Answer : The value of diffusion coefficient is, 
Explanation :
Formula used :

where,
D = diffusion coefficient = ?
= 
= 
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get:


Thus, the value of diffusion coefficient is, 