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Grade 2 · lesson 3 of 4

Describe reversible changes

Describe reversible changes using supplied evidence and a solved model.

About 12 minutes, plus any extended practice

Download the grade pack

Supplied materials

  • For younger learners, an adult may read each direction aloud; pointing, drawing and spoken explanations count as responses.
  • Paper, drawing space or a browser document.
  • Reference card A: solid changes to liquid. Reference card B: liquid changes to solid.
  • Assessment case 1: Which scientific label fits the specifically described step or feature? Supplied case: Ice becomes liquid water.
  • Assessment case 2: Which scientific label fits the specifically described step or feature? Supplied case: Water becomes ice.
  • Assessment case 3: Which scientific label fits the specifically described step or feature? Supplied case: Paper becomes strips.
  • Assessment case 4: Which scientific label fits the specifically described step or feature? Supplied case: A supplied record describes iron rusting.
  • Assessment case 5: Which scientific label fits the specifically described step or feature? Supplied case: Frozen water warms into liquid.
  • Assessment case 6: Which scientific label fits the specifically described step or feature? Supplied case: Liquid water cools into ice.

Learn the idea

Melting and freezing change state without changing the substance’s identity. Cutting changes shape. Some changes form new substances and cannot be simply reversed by restoring temperature.

Melting means solid changes to liquid. Freezing means liquid changes to solid. Cutting means material divided into smaller pieces. Chemical change means new substances are produced.

For melting, look for the clue “solid changes to liquid.” For freezing, look for “liquid changes to solid.” More than one process can happen in a real situation. Answer about the one described in this question.

  1. Read or listen to the four science words and what each means. Say how the first two differ.
  2. Choose two of the short cases. Point to the clue that helps you choose a science word for each one. You may draw or say your answer.
  3. Answer each practice question. Say which clue helped you, then check the explanation.
  4. Use the extra task to make two examples that show different science words. Draw or say what makes each one fit.
Worked example

See the method in action

Worked reference-card problem: a card states “solid changes to liquid”; a second states “liquid changes to solid.” The first fits melting and the second fits freezing. The reason is the described function or change, not the order of the cards or a favorite name. If their descriptions exchange places, their category labels exchange too. Keep the supplied descriptions attached to the correct case.

Your turn

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Helpful tips
  • Use the feature “solid changes to liquid” to justify melting; do not sort by the name alone.
  • Distinguish freezing (liquid changes to solid) from a different process occurring in the same situation.
Which scientific label fits the specifically described step or feature? Supplied case: Ice becomes liquid water.

Feedback appears here after you check. This is practice, not a graded school assessment.

See the answer and explanation

melting

The answer is melting. In the notes, it means “solid changes to liquid.” Melting and freezing change state without changing the substance’s identity. Cutting changes shape. Some changes form new substances and cannot be simply reversed by restoring temperature.

Take it further

Create one new case showing melting and one showing freezing. Expected: the first explicitly shows “solid changes to liquid”; the second explicitly shows “liquid changes to solid.” Explain the distinction by drawing, speaking or writing. A label without a matching feature is incomplete.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.

More practice: try new cases

Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.

More practice: try new cases
1. Which scientific label fits the specifically described step or feature? Supplied case: Water becomes ice.
Need a hint?
  • Look for the described feature: liquid changes to solid.
  • Compare the clue with each science word. Use only what the case tells you; do not add a new event.
2. Which scientific label fits the specifically described step or feature? Supplied case: Paper becomes strips.
Need a hint?
  • Look for the described feature: material divided into smaller pieces.
  • Compare the clue with each science word. Use only what the case tells you; do not add a new event.
3. Which scientific label fits the specifically described step or feature? Supplied case: A supplied record describes iron rusting.
Need a hint?
  • Look for the described feature: new substances are produced.
  • Compare the clue with each science word. Use only what the case tells you; do not add a new event.

Your choices are temporary. Feedback appears after you check all the answers.

Nothing here is saved to an account or sent to a teacher. Keep your own notes or download them before leaving. The score describes these questions; it does not certify subject mastery.

Check the subject sources

These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.