Question

claim - evidence - reasoning
phase change as a physical change
a substance can exist in different phases, such as a solid, liquid, or gas. when the temperature changes, the substance may change phase. for example, below 0°c, h₂o is found as solid ice. when heated, this ice melts to form liquid water. in another example of a phase change, when solid co₂ (known as dry ice) warms, it turns directly into a gas.
build your argument through claim, evidence, and reasoning

1. sep construct written arguments is a phase change a physical change or a chemical change? use the claim - evidence - reasoning framework to build a scientific argument. after stating your claim, support it with evidence and scientific reasoning.

make a claim your claim should be a response to the stated question. place only what you intend to argue. if appropriate, use relevant vocabulary you have learned in this course.
cite evidence/data provide at least 2 observations that can be used to justify your claim. avoid \i\ statements. if possible and appropriate, use multiple sources.
use reasoning if applicable, state the definition(s) of the vocabulary used in the claim in your own words. then summarize the data and state how that aligns with the definition and verifies the claim. if there is a known relevant scientific principle that explains the phenomena, state that and use it to explain what causes your claim to be true. be as detailed as possible.
a phase change is a physical change
when water freezes into ice
when water boils to form steam
a physical change is a change that in the form or state of matter without altering the chemical composition for ex when water freezes into ice, its chemical composition remains the same, the only thing that changes from liquid to solid, and when water boils to form steam, the chemical identity of water molecules remains unchanged
evaluate and revise your argument

1. sep critique share your written argument so that it can be critiqued by one or more classmates. listen closely and record their feedback. what flaws or weaknesses did your peers identify in your argument? if a counter - argument was proposed, do you agree or disagree with the reasoning?
2. sep evaluate evidence and reasoning based on the feedback you have received, write an improved draft of your argument.

revise the claim write only the claim. while revising your claim, consider the following:
was the original claim flawed?
how might you modify it in response to criticism?
reassess the evidence provide at least 2 pieces of evidence for your new claim.
consider:
any previous evidence that is applicable,
new or previously missed evidence that is relevant that can strengthen your claim, and
any existing evidence that can be interpreted differently.
reinforce the reasoning as before, use your evidence, definitions, and scientific knowledge to justify your claim.
consider:
ways to strengthen your reasoning,
providing very detailed explanations, and
if applicable, add reasoning to refute alternative explanations.

Explanation:

1. Initial Argument: A phase change is a physical change. Evidence includes water freezing into ice and boiling into steam. Reasoning is based on the definition of a physical change - a change in form or state without altering chemical composition. For example, water's chemical identity remains the same during freezing and boiling.
2. Critique and Feedback: Classmates may identify weaknesses like lack of more diverse evidence or not addressing potential counter - arguments clearly. If a counter - argument is proposed, one must evaluate its reasoning.
3. Improved Draft:

• Revised Claim: A phase change is a physical change as it only modifies the state of matter while keeping the chemical composition constant across various substances.
• Reassessed Evidence: When solid naphthalene sublimes into a gas and when liquid mercury freezes into a solid.
• Reinforced Reasoning: A physical change is characterized by no change in the chemical formula of the substance. In the case of naphthalene sublimation and mercury freezing, the chemical identities of naphthalene ($C_{10}H_8$) and mercury (Hg) remain unchanged. This aligns with the scientific principle that phase changes are physical changes.

Answer:

1. Initial claim: A phase change is a physical change. Evidence: Water freezing into ice, water boiling into steam. Reasoning: Physical change is a change in form/state without altering chemical composition, as seen in water phase changes.
2. Await feedback from classmates to identify flaws/weaknesses and evaluate counter - arguments.
3. Revised claim: A phase change is a physical change as it only modifies the state of matter while keeping the chemical composition constant across various substances. Reassessed evidence: Naphthalene sublimation, mercury freezing. Reinforced reasoning: Chemical identities remain unchanged in these phase changes, consistent with the principle of physical changes.