The burning of wood is an example of an oxidation-reduction reaction

Solution:

Yes, burning of wood is an example of oxidation-reduction reaction.  

Oxidation-reduction reaction is also known as redox reaction. In this reaction, oxidation and reduction both takes place simultaneously such that one of the species gets oxidized and other gets reduced.

Wood is made up of cellulose which is a carbohydrate. Thus, there are carbon and hydrogen bonds present. On burning, large amount of heat is released due to breaking of these hydrogen and oxygen bonds. Here, hydrogen gets oxidized to water and carbon gets oxidized to carbon dioxide. Similarly, oxygen get reduced here. Since, both oxidation and reduction processes are taking place, the burning of wood is a redox reaction.

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.