Answer:
None of the species in the equation have undergone either oxidation or reduction
Explanation:
The easiest way to see if oxidation or reduction has happened is to compare oxidation numbers of each and every species before and after the reaction.
Calcium is two before the reaction and two after the reaction
Hydrogen is -1 before the reaction and -1 after the reaction
Sodium is one before the reaction and one after the reaction
Iodine is -1 before the reaction and -1 after the reaction.
For an oxidation to happen an increase in oxidation number has to happen.
For a reduction to happen, a decrease in oxidation number has to happen. None have happened
Water left in a freezer is called ice
An ecosystem is a lot of things and places that need each other to survive
Hydrogen burns with oxygen as in combustion reaction to form water.
H₂ + O₂ → H₂O