A substance where almost all have the same atomic number of protons
It is not a chemical change because a chemical change is when the substance changes to a whole new substance (ex rust on a car) ex2(fire burning wood) it’s not the same substance) it is a physical change because it’s still water basically (ex: like melting ice, it’s still ice( not a whole different substance)
Answer:
120.575 kJ is the activation energy for the souring process.
Explanation:
The formula for an activation energy is given as:
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at
= 
= rate constant at
= 
= activation energy for the reaction = ?
R = gas constant = 8.314 J/mole.K
= initial temperature = 
= final temperature = 
Now put all the given values in this formula, we get:l
![\log (\frac{k}{40k})=\frac{Ea}{2.303\times 8.314 J/mol K}[\frac{1}{298K}-\frac{1}{277 K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7Bk%7D%7B40k%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%208.314%20J%2Fmol%20K%7D%5B%5Cfrac%7B1%7D%7B298K%7D-%5Cfrac%7B1%7D%7B277%20K%7D%5D)

120.575 kJ is the activation energy for the souring process.
Explanation:
Formula for black body radiation is as follows.

where, P = power emitted
A = surface area of black body
= Stephen's constant = 
As area is given as 1.0
. Converting it into meters as follows.
(as 1 m = 100 cm)
= 
It is given that P = 201 watts. Hence,
= 
= 
T = 
= 8862.5 K
Thus, we can conclude that the temperature of the surface is 8862.5 K.
The correct answer is hotter