Question

lesson objective students will be able to differentiate between physical and chemical changes and explain whether a phase change is a physical or chemical change using claim - evidence - reasoning (cer). language objective students will use scientific vocabulary (e.g., phase change, physical change, chemical change, new substance, properties) and complete sentence frames to write and explain their cer in new situations. build background - physical change = changes the form or state of matter but does not make a new substance; no new products with new properties. - examples: melting butter, boiling water, dissolving sugar, breaking glass. - chemical change = makes a new substance with new properties. - examples: frying an egg, burning wood, rusting iron, baking bread. chemical and physical changes chemical change: a physical change: matter chemical reaction forms changes form but not chemical identity. new products. combustion rotting melting shredding rusting digestion boiling chopping cer framework instructions: read the guiding question: is a phase change a physical or a chemical change? - write a claim. - support your claim with evidence. - use reasoning to explain how your evidence proves your claim. - use the word bank below to help you build complete responses. word bank phase physical chemical substance same new state of change change change substance matter solid, liquid, melt freeze boil condense properties remains gas the same changes evidence this proves... permanently shows... claim answer the question: is a phase change a physical or chemical change? - i claim that a phase change is a ____ change because evidence use at least 2 pieces of evidence: - my evidence is that when a __ happens, the substance is still - another piece of evidence is reasoning explain why your evidence supports your claim: - this evidence supports my claim because a __ change means - a chemical change would __, but in a phase change - therefore, a phase change is a ____ change. exit ticket label the six phase changes occurring in the diagram. sublimation condensation freezing melting evaporation deposition solid liquid gas

Explanation:

A phase change is a physical change as it only alters the form or state of matter (like melting, boiling) without creating a new substance. For example, when ice melts into water, it's still H₂O. Evidence includes that during melting, the substance's chemical identity remains the same and during boiling, no new substances are formed. Physical change means altering the form or state of matter without changing its chemical identity. A chemical change would produce new substances with different properties, but in a phase change this doesn't occur.

Answer:

Claim: physical
Evidence:

• My evidence is that when a melting happens, the substance is still the same substance chemically.
• Another piece of evidence is when boiling occurs, no new substances are formed.

Reasoning:

• This evidence supports my claim because a physical change means changing the form or state of matter without changing its chemical identity.
• A chemical change would produce new substances with new properties, but in a phase change the chemical identity remains the same.
• Therefore, a phase change is a physical change.

Exit Ticket (from left - right in the diagram): melting, evaporation, condensation, freezing, sublimation, deposition