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Back Again, or Not is a free printable Grade 2 science worksheet on changes from heating and cooling that reverse and that do not, aligned to NGSS performance expectation 2-PS1-4. It prints 3 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two students in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.

Set 1 of 25 · the same problems every time you open this link.

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One paper per student

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All 25 sets ask different questions.

Back Again, or Not

2-PS1-4

NameDate

Sort each change into the right group.

1.Sort each one: Can be changed back or Cannot be changed back?

Sort: Wax melted in a warm dish, Wood burnt to ash, Chocolate melted, then cooled, A cake baked from batter

Can be changed backCannot be changed back
2.Sort each one: Can be changed back or Cannot be changed back?

Sort: Water boiled into steam under a lid, Bread toasted, An egg cooked hard, Water frozen into ice

Can be changed backCannot be changed back
3.Sort each one: Can be changed back or Cannot be changed back?

Sort: Clay fired in a kiln, Milk left until it curdles, Ice cream left out and refrozen, Butter melted in a pan

Can be changed backCannot be changed back

LessonPrint · 2-PS1-4 · Set 1 · free to copy for classroom use

Answer key — Back Again, or Not

Set 1. Prints on its own sheet.

  1. 1.1. A cake baked from batter — Cannot be changed back 2. Chocolate melted, then cooled — Can be changed back 3. Wax melted in a warm dish — Can be changed back 4. Wood burnt to ash — Cannot be changed back
  2. 2.1. An egg cooked hard — Cannot be changed back 2. Bread toasted — Cannot be changed back 3. Water boiled into steam under a lid — Can be changed back 4. Water frozen into ice — Can be changed back
  3. 3.1. Butter melted in a pan — Can be changed back 2. Clay fired in a kiln — Cannot be changed back 3. Ice cream left out and refrozen — Can be changed back 4. Milk left until it curdles — Cannot be changed back

Questions about Back Again, or Not

What does the Back Again, or Not worksheet cover?

It practices changes from heating and cooling that reverse and that do not — 3 questions for Grade 2, all on NGSS 2-PS1-4: Argue with evidence that some changes from heating or cooling undo and some do not. The instruction to students is “Sort each change into the right group”, and the answer key follows on the next sheet.

Which NGSS performance expectation does Back Again, or Not practice?

2-PS1-4, under Physical Science for Grade 2. The published performance expectation reads: “Construct an argument with evidence that some changes caused by heating or cooling can be reversed and some cannot.” The worksheet assesses that performance expectation rather than a paraphrase of it.

What age or grade is this worksheet for?

Back Again, or Not is written for Grade 2, typically ages 7-8. It is one of the sheets on 2-PS1-4, so it suits any student working at that standard — including older students revisiting it and younger ones working ahead.

Does Back Again, or Not come with an answer key?

Yes. All 3 answers are generated from the same problems as the questions, so the key cannot drift out of step with the sheet. It starts on a fresh sheet of paper, after the questions, so it is not handed out with the class by accident.

How many different versions of Back Again, or Not can I print?

25 — one per student, and all 25 ask different questions. Set 1 downloads the whole class as a single PDF. Every version is fixed to its own address, so a sheet printed today holds the same problems when you reopen it next week.

Is Back Again, or Not free to print and photocopy?

Yes. Back Again, or Not, its answer key and its 25 versions are free to print and photocopy for your own class, with no account, no email capture and no subscription at the download step. Please do not resell them or republish them as your own.

Is there a lesson plan to teach 2-PS1-4?

Yes — “Back Again, or Not” is a 50-minute Grade 2 plan for 2-PS1-4, timed section by section, with the misconceptions to expect and an exit ticket. Back Again, or Not is the practice that follows it.

More practice for 2-PS1-4

Argue with evidence that some changes from heating or cooling undo and some do not.

Teaching this next? Back Again, or Not is the 50-minute plan for it, with the misconceptions to expect.

All Grade 2 worksheets

Last reviewed 2026-09-05. Aligned to 2-PS1-4 of the Next Generation Science Standards.