If you look at many different organisms, you will see similar structures. Like humans have a forearm, birds have a wing, whales have fins, leopards have legs. The bones evolvolved to fit the animal
The liquid is blue is an example of qualitative data. Qualitative data is data that can not be represented by numbers. The volume and density are both quantitative data.
It comes from the chemical reaction of The wax and the gas because the wax is made up of carbon-based chemicals so the gas and carbon make the candle light =)
