Build a raft describing the physical and chemical properties of the raft

well, first of all you would need to know what the raft is being made of. take wood for an example. so you need to list the physical and chemical properties of wood. physical properties can be observed or measured. so one physical property of wood might be it's volume, or it's state, or it's strength, or it's hardness, or many other things that can be measured or observed. next you need to find the wood's chemical properties a chemical property describes how a substance changes into a new substance, either by combining with other elements or by breaking apart into new substances. so a chemical property of wood might be it's flammability, or it's reactivity.