Answer:
0.023
Explanation:
The Arrhenius' equation states that:

Where k is the velocity constant of the reaction, A is the constant of the collisions, Ea is the activation energy (the energy necessary to the molecules have so the reaction will happen), R is the gas constant (8.314 J/molK) and T is the temperature.
This equation is derivated of:
k = pZf
Where
p=fraction of collisions that occur with reactant molecules properly oriented
f=fraction of collisions having energy greater than the activation energy
Z=frequency of collisions
Thus, p*Z = A, and
f = 
So, if the energy of the molecules is 12.5 kJ/mol = 12500 J/mol, thus the fraction will be:
f = 
f = 0.023
Answer:3.5 moles * 6.02 X 10^23 particles/mole * 2 H atoms/particle of H2 = 42.14 X 10^^23 atoms
Explanation:
When energy is needed in order for the reaction to happen, then that reaction is known as endotermic. When the reaction has as a result energy then it is exotermic. An example of an endotermic reaction would be photosynthesis, for an exotermic: combustion.
Li+ have<span> more</span> elements i think