No, the student's conclusion is not accurate. In the demonstration of water changing into steam, only a physical change occurs. This is because water vapor is still composed of water molecules, just in a different state (gaseous instead of liquid). The chemical composition of the water molecules remains the same.
On the other hand, in the demonstration of a piece of wood burning and producing smoke, a chemical change occurs. Burning or combustion involves a chemical reaction where the wood reacts with oxygen in the air to produce heat, light, and various gases, including smoke. The chemical composition of the wood is altered in this process.
So, while both demonstrations involve the production of a gas, only in the case of burning wood is there a chemical change taking place.
A class observes to demonstrations. Water changing into steam and a piece of wood burning and producing smoke. A student concludes that both the demonstrations must be examples of a chemical change because a gas is produced in each. Is the students conclusion accurate? Explain your answer, referring to both demonstrations.
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