Text: Identifying the Reddish-Brown Substance Chapter 1 Question: What is the reddish-brown substance in the water? Claim 1: The reddish-brown substance is the same as the substance that makes up the pipes. Claim 2: The reddish-brown substance is the same substance as the fertilizer. Claim 3: The reddish-brown substance is not the same as either the fertilizer or the substance that makes up the pipes. Dr. Yung wants you to explain what the reddish-brown substance is to the people of Westfield. As you write your argument, remember to: – State your claim about the identity of the reddish-brown substance. – Use evidence from both your observations and the atomic-scale models to support your claim. – Include all the vocabulary words listed below in your argument.
The Correct Answer and Explanation is:
Claim: The reddish-brown substance in the water is the same as the substance that makes up the pipes.
Explanation:
The reddish-brown substance found in Westfield’s water is rust, which is formed when iron from the pipes reacts with oxygen and water. This conclusion is supported by both observations and atomic-scale models. When we examined the substance closely, we noticed that it appeared as flakes or particles that resembled corrosion. Additionally, the atomic model of the reddish-brown substance showed it contained iron (Fe) and oxygen (O) atoms bonded together, forming iron oxide (Fe₂O₃) — the chemical name for rust.
We compared this with a sample of the pipes, which are made of iron. The atomic model of the pipes also showed only iron atoms. When iron reacts with water and oxygen, especially over time or in old pipes, it forms rust. This means the chemical reaction between the pipe material and the water causes the formation of the reddish-brown substance.
In contrast, the atomic model of the fertilizer showed a completely different structure. Fertilizer contained atoms like nitrogen (N), phosphorus (P), and potassium (K), none of which matched the iron and oxygen structure of the reddish-brown substance. Therefore, Claim 2 is incorrect.
Claim 3 is also incorrect because the atomic structure of the reddish-brown substance matches the rust formed from iron pipes and not any other material.
This evidence proves that the reddish-brown substance is chemically identical to rust, formed from the breakdown of the iron pipes. The reaction that creates rust is a natural process that occurs when iron is exposed to oxygen and moisture, and this matches the environmental conditions in Westfield’s water system.
Vocabulary words used: atomic-scale models, chemical reaction, iron, oxygen, fertilizer, atoms.
