Ok A is the correct answer
Answer:
+3
Explanation:
The oxygen all have a -2 oxidation state. (peroxides are exceptions)
The chemical structure is symmetrical. Both carbon are equivalent.
2 (oxidation state of carbon) + 4 (oxidation state of oxygen) = charge of ion.
2 (oxidation state of carbon) + 4 (-2) = -2
oxidation state of carbon = +3
The given question is incomplete. The complete question is :
It takes 151 kJ/mol to break an iodine-iodine single bond. Calculate the maximum wavelength of light for which an iodine-iodine single bond could be broken by absorbing a single photon. Be sure your answer has the correct number of significant digits.
Answer: 793 nm
Explanation:
The relation between energy and wavelength of light is given by Planck's equation, which is:

where,
E = energy of the light = 151 kJ= 151000 J (1kJ=1000J)
N= moles = 1 = 
h = Planck's constant = 
c = speed of light = 
= wavelength of light = ?
Putting in the values:


Thus the maximum wavelength of light for which an iodine-iodine single bond could be broken by absorbing a single photon is 793 nm
Well there's a couple reasons why. First, the land itself can become “tired" and less fertile<span>. This is because the same type of </span>crop<span> planted repeatedly in the same area keeps draining the land of the same nutrients needed for that plant's growth. Pest can also plant their nest near the crop if the farmer continues to plant the same crop in the same place.
Which is the reason why things such as "crop rotation" exist to keep things fresh, and prevent what I described above from happening.</span>
4 grams , mass cannot be created or destroyed. it has to be the same on both sides of the equation