Assign an oxidation number to each elementary in the following compounds or ions n2o5

Oxidation number per Nitrogen +5, oxidation number per Oxygen -2

Explanation:

So we know that oxidation number of Oxygen is -2 so we have -2x5= -10 charge. This gives a total oxidation number charge of -10 for the five oxygen atoms in N2O5. To maintain electrical neutrality, as required for all compounds, the two nitrogen atoms must have a total oxidation charge of +10, so that each of the two nitrogen atoms has an oxidation number of +5

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.