Hypothesis: Not all solids are irreversible when burned.

Predictions: I predict that the chocolate and candle will melt, and they are reversible changes while the wood and paper will burn into ashes/charcoal. However, the paperclips are composed of two different materials, so the outer layer will melt because it's plastic, while the inside will not burn because its metal. 

Results: The wood burned slowly and released some as it burned. The burst wood turned very quickly and quietly turned to a white, grey-coloured ash. Hudayfa K