Open-and-go lessons that inspire kids to love science.

Science curriculum for K—5th grades.

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  • NGSS-aligned and Common Core make the transition to the Next Generation Science Standards and support Common Core.
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Chemical Magic

Chemical Reactions & Properties of Matter

  1. Lessons
  2. Activity Prep
  3. Assessments

Mystery 1: Introduction to Chemistry

Test Like An Alchemist

In this activity, your students will test liquids to see which ones can clean the tarnish off a penny. Then, when one penny changes from dark and dirty to bright and shiny, they’ll have a chance to think about where the tarnish went. In a class, this activity works best when students work together in groups of four, but students can also work alone.

Two quick notes:

  • Review the instructions in Step 4 before you begin. In the next Mystery, you’ll need to reuse some of the materials from this Mystery so students can copperplate a steel nail.
  • If you’re working with a small group or solo student, you can make 1 cup of each solution, rather than 2 (see Step 3). When you set up your stations, just cut the “recipes” in half.

Step 1: Plan ahead

You’ll need old, tarnished pennies for this activity. For best results, use pennies dating from BEFORE 1982, when they were made from 95% copper. (Pennies made after 1982 are copper-plated zinc, which won’t work for this activity; in 1982, both varieties were made.)

If you’re working with a class, we suggest asking students to bring in pennies made before 1982. You can also buy penny rolls at the bank. We bought $3 worth, sorted out the pre-1982 pennies, and had exactly 40 to work with.

Step 2: Get your supplies

You'll need:

  • pre-1982 tarnished pennies (You’ll need at least one for each student, plus a few extras—that’s about 40 pennies for a class of 32. If you have a small group or solo student, you’ll need at least 20 pennies.)
  • measuring spoons and cups
  • 4 plastic food-storage containers that hold just over 3 cups each, like these. (You’ll need one container for each test station.)
  • tape for labeling containers
  • 4 cups of water
  • 2 tablespoons of liquid detergent
  • 4 cups of white vinegar (You’ll use vinegar again in Chemistry Mysteries 3, 4, and 5, so we suggest getting a gallon.)
  • 1 cup of salt (You’ll use another cup of salt in Chemistry Mystery 3, so we suggest getting a 26-ounce container.)
  • steel nails (Note that it’s important that you get steel nails like these—NOT stainless-steel nails, and NOT galvanized nails. We recommend asking at your local hardware store. If you can’t find steel nails, you can substitute steel washers as long as they are not galvanized and not stainless steel. You can also substitute jumbo paper clips.)
  • optional: an orange and a brown colored pencil for each group of students (For coloring dull and shiny pennies on worksheets.)

Step 3: Prepare for class

Print out these materials:

Prepare these four testing liquids in your labeled containers and set up separate test stations:

  • Station 1: Mix 2 tablespoons liquid detergent with 2 cups water in the Soapy Water container.
  • Station 2: Pour 2 cups of vinegar into the Vinegar container.
  • Station 3: Mix 6 tablespoons salt with 2 cups vinegar in the Salty Vinegar container. (It won't all dissolve, but add it anyway.)
  • Station 4: Mix 6 tablespoons salt with 2 cups water in the Salty Water container. (It won't all dissolve, but add it anyway.)

Step 4: After class—including preparation for the next Mystery

  • Save student work: Students will need their completed “Alchemist’s Potion” worksheets for the next Mystery. Make sure they’re stored somewhere safe.

  • Save the pennies in the Salty Vinegar solution: At the end of this Mystery, you’ll dump all the pennies into the Salty Vinegar to soak overnight. (If you made just 1 cup of salty vinegar, dump all 20 pennies into it.)

  • Add a nail: After students have left class, we recommend that you put a nail into the Salty Vinegar solution with the pennies—but don’t tell your students you’re doing it. You’ll find out why in the next Mystery, when your students will discover that the solution the pennies soaked in can change steel nail in a surprising way.

Mystery 2: Particulate Nature of Matter

The King's Sword

To do this activity, you must have completed the activity in Mystery 1.

In this activity, students will add copper to a steel nail using the copper-rich solution made in Mystery 1. Students will work together in teams of four. Students working alone will need a helper for some steps, but should be able to do most of the activity on their own.

Step 1: Plan ahead

At the end of the last Mystery, you put all the pennies in a vinegar-and-salt solution, added a steel nail when students were gone, and then left the solution overnight. To prepare for this activity, check on that solution before class and look at the nail you put in. All or part of the nail should now be covered by a layer of copper.

Take the nail out of the solution, rinse it off, and set it aside to show your students during the last video. Save the penny-filled solution for students to use in this activity.

Students will also need the “Alchemist’s Potion, Part 1” worksheets that they completed in Mystery 1.

Step 2: Print out materials and get supplies

For the classroom, you’ll need:

  • the penny-filled salt-and-vinegar liquid from Mystery 1
  • the “Alchemist’s Potion, Part 1” worksheets students completed in Mystery 1
  • 4 plastic spoons (for students to scoop up the solution and pennies)
  • a plastic box or bin, plus binder clips or clothespins (to keep bags for students who need to leave their experiments overnight)
  • paper towels (for cleanup)

Each student will need:

Each group of four students will need:

  • a plastic or paper plate
  • 2 stick-on labels (or one label and a strip of masking tape)
  • a ziplock bag (either snack-size or sandwich-size will work)
  • a steel nail (As noted in Mystery 1 Activity Prep, it’s important to use steel nails like these—NOT stainless-steel nails, and NOT galvanized nails. If you can’t find steel nails, you can substitute steel washers as long as they are not galvanized and not stainless steel. You can also substitute jumbo paper clips.)
  • a 3-ounce paper cup (we use bathroom cups, also known as Dixie cups)
  • orange, brown, and grey pencils, crayons, or markers for drawing and to write on labels (optional)

Step 3: Prepare for class

To distribute materials quickly and easily, we recommend you set out plates, labels, and pencils or markers for each group, and then set up three stations for student use:

  • Station 1: Pennies in the vinegar-and-salt solution along with the spoons for scooping up pennies and one Dixie cup for each group
  • Station 2: A plastic bag for each group
  • Station 3: A steel nail for each group

Step 4: After class

If conditions are just right, copper forms on the steel quickly. But in many cases, students may need to leave their experiments for a few hours or even overnight to see results.

To store students' experiments overnight, we suggest clipping the bags to the sides of a plastic box or bin, with the bags hanging over the inside of the box. This ensures that the nail remains submerged in the liquid. In the unlikely event that one of the bag leaks, the bin will catch the vinegar.

To do this activity, you must have completed the activity in Mystery 1.

In this activity, students will add copper to a steel nail using the copper-rich solution made in Mystery 1. Students will work together in teams of four. Students working alone will need a helper for some steps, but should be able to do most of the activity on their own.

Step 1: Plan ahead

At the end of the last Mystery, you put all the pennies in a vinegar-and-salt solution, added a steel nail when students were gone, and then left the solution overnight. To prepare for this activity, check on that solution before class and look at the nail you put in. All or part of the nail should now be covered by a layer of copper.

Take the nail out of the solution, rinse it off, and set it aside to show your students during the last video. Save the penny-filled solution for students to use in this activity.

Students will also need the “Alchemist’s Potion, Part 1” worksheets that they completed in Mystery 1.

Step 2: Print out materials and get supplies

For the classroom, you’ll need:

  • the penny-filled salt-and-vinegar liquid from Mystery 1
  • the “Alchemist’s Potion, Part 1” worksheets students completed in Mystery 1
  • 4 plastic spoons (for students to scoop up the solution and pennies)
  • a plastic box or bin, plus binder clips or clothespins (to keep bags for students who need to leave their experiments overnight)
  • paper towels (for cleanup)

Each student will need:

Each group of four students will need:

  • a plastic or paper plate
  • 2 stick-on labels (or one label and a strip of masking tape)
  • a ziplock bag (either snack-size or sandwich-size will work)
  • a steel nail (As noted in Mystery 1 Activity Prep, it’s important to use steel nails like these—NOT stainless-steel nails, and NOT galvanized nails. If you can’t find steel nails, you can substitute steel washers as long as they are not galvanized and not stainless steel. You can also substitute jumbo paper clips.)
  • a 3-ounce paper cup (we use bathroom cups, also known as Dixie cups)
  • orange, brown, and grey pencils, crayons, or markers for drawing and to write on labels (optional)

Step 3: Prepare for class

To distribute materials quickly and easily, we recommend you set out plates, labels, and pencils or markers for each group, and then set up three stations for student use:

  • Station 1: Pennies in the vinegar-and-salt solution along with the spoons for scooping up pennies and one Dixie cup for each group
  • Station 2: A plastic bag for each group
  • Station 3: A steel nail for each group

Step 4: After class

If conditions are just right, copper forms on the steel quickly. But in many cases, students may need to leave their experiments for a few hours or even overnight to see results.

To store students' experiments overnight, we suggest clipping the bags to the sides of a plastic box or bin, with the bags hanging over the inside of the box. This ensures that the nail remains submerged in the liquid. In the unlikely event that one of the bag leaks, the bin will catch the vinegar.

Mystery 3: Acids, Reactions, & Properties of Matter

Acid Test

In this activity, students discover two ways to detect acids. Then they test condiments and other foods to figure out which ones are acids.

Step 1: Think ahead

For a class or large group, we suggest students work in groups of four at a workstation where they can share supplies. Within each group, students will work with a partner. Students working at home can work on their own or with a partner.

Before buying supplies, figure out how many groups you’ll have, so you can set up supplies accordingly.

Step 2: Gather equipment and supplies

To prepare for class, you’ll need:

  • measuring spoons and cups
  • scissors
  • a sharpie or permanent marker
  • 1 cup of dry black beans or 2 cups of chopped raw purple cabbage
  • 2 cups of water
  • a container that can hold at least 4 cups of water (for making purple indicator liquid; see Step 4 for instructions)
  • 20 drinking straws (you’ll be modifying these so students can use them for transferring liquids; see Step 4 for instructions)
  • at least two foods or drinks that students can test for acidity (Anything in the kitchen is fair game. You can keep it simple and have students all test the same foods, or give every group something different to test. We recommend choosing at least one acid, such as lemonade, ketchup, mustard, pickle juice, yogurt, or sour cream, and one non-acid, such as mayonnaise, milk, or soy sauce. You’ll need about 1 cup of each for a class of 32.)

For each group of four students (or each solo student), you’ll also need:

  • newspaper or plastic to cover work areas
  • baking soda (about 1 tablespoon; 8 groups need about half of a 1-pound box)
  • baking powder (about 1 tablespoon; 8 groups need about 7 ounces)
  • vinegar (about 2 tablespoons; 8 groups need about 2 cups)
  • water (about 2 tablespoons; 8 groups need about 2 cups)
  • 2 craft sticks or spoons (for spooning out powders; 8 groups need 16 craft sticks or spoons)
  • 7 small paper cups: 5 for testing known substances, and 2 for testing unknowns (We used 3-ounce bathroom cups, also known as Dixie cups. For 8 groups, you’ll need a total of 56 cups.)

For each pair of students working together (or each solo student) you’ll need:

  • a sheet of Press’n Seal sealable plastic wrap; you can also substitute taped-down waxed paper (For 8 groups, you’ll need 16 sheets.)
  • a few toothpicks (for mixing samples)
  • paper towels (for cleanup)

Step 3: Print out materials

Each table will need:

Each pair of students will need:

Each student will need:

Here is a "Results Answer Key" for you to reference if needed.

Step 4: Prepare for class

Cut straws in half to make short straws. Students will use these to transfer drops of liquid. (Full-length straws are likely to tip over cups.) For a class of 32, we suggest you cut 20 full-sized straws in half. That gives you 5 short straws per group—3 for initial testing and 2 for testing unknowns.

Make the purple indicator liquid. For a class of 32, you’ll need about 1 cup. (If you’re using black beans, put 1 cup of beans into 2 cups of water and leave them for at least an hour. The beans will soak up some water and turn the rest purplish brown. If you’re using purple cabbage, put 2 cups of chopped cabbage in 1½ cups of water. Leave it for at least an hour, stirring occasionally. The cabbage will turn the water purple.)

To distribute each group’s materials quickly and easily, we recommend you set up three supply stations.

Station A: Acid Reaction Supplies

  • “Acid Reaction Supplies” sheets (1 per group)
  • a cup containing 2 tablespoons of water (1 per group)
  • a cup containing 2 tablespoons of vinegar (1 per group, labeled “V” with marker so students can quickly tell it from the water)
  • short straws (2 per group)

Station B: Testing Supplies

  • “Testing Supplies” sheet (1 per group)
  • a cup containing 2 tablespoons of baking soda (1 per group; note that you may want to tell students that baking soda is different from baking powder)
  • a cup containing 1 tablespoon of baking powder (1 per group, labeled “BP” with marker so students can quickly tell it from the baking soda)
  • a cup containing 1 tablespoon of purple indicator liquid (1 per group)
  • craft sticks or spoons (2 per group)
  • short straw (1 per group)

Station C: Unknowns

  • a cup containing 1 tablespoon of each unknown substance used for testing (we recommend two test substances per group, each in its own cup)
  • a short straw for each test cup
  • a toothpick for each test cup


Teacher Tips

The purple liquid that you prepare from the cabbage is called an indicator. There’s a pigment in purple cabbage that changes color when it reacts with an acid or base. You and your students should notice that the color of the cabbage juice changes to a reddish/pink when you add it to any of the acids (e.g. vinegar). You can then use this information to test unknown liquids. If the liquid turns pink, then it’s an acid. You can learn more about cabbage juice indicator here.

You and your students will also notice that when baking soda is mixed with vinegar, there is fizzing that indicates an acid-base reaction. Baking powder will also fizz with vinegar. But you will notice that baking powder will also slightly fizz when water is added. This is because baking powder is actually a mixture of baking soda (base) and cream of tartar (acid). This is why it reacts with both water and vinegar.

Mystery 4: Chemical Reactions

The Great Goo Experiment

This is a two-part activity. In Part 1, students experiment by combining different substances and watching for reactions. In Part 2, students make “Mystery Science Goo” in ziplock bags and observe its properties. If the activity is running long, you can save the second part for another day.

Step 1: Think ahead

If you have a class or group of students, students can work in pairs and share supplies with others at their table or pod. To figure out quantities of supplies, start by figuring out many pairs and how many tables you’ll have. Individual students can work alone.

Step 2: Gather equipment and supplies

To prepare for the activity, you’ll need:

  • a permanent marker
  • a ruler
  • a measuring cup
  • a teaspoon for measuring (abbreviated as tsp)
  • a tablespoon for measuring (abbreviated as Tbsp)
  • a bottle that holds at least a half gallon (check the recycling bin)
  • a bottle that holds at least a pint (check the recycling bin)
  • a large jar or bowl for mixing glue and water
  • lots of water

The table below shows supplies with amounts needed for a pair of students or a single experimenter, and also for a class of 32 students working in pairs. Since each pair shares supplies with another pair of students at a table, you need one set of testing supplies for each group of four students.

Supplies for Part 1 (Testing for a Reaction)

Supply Quantity for 1 Pair or Individual Quantity for 16 Pairs Working at 8 Tables Notes
Set of printouts (2 pages) Answer Key for Teachers 1 set 16 sets Each pair of students needs a set of printouts.
White vinegar 1 Tbsp ½ cup
Milk 1 Tbsp ½ cup
Borax powder 2 tsp 2 tsp You will mix this with one cup of water. Note that you’ll need more borax powder for Part 2.
Baking soda 1 tsp 1 tsp You will mix this with one cup of water.
Elmer’s multipurpose glue 1 Tbsp 4 Tbsp (about 1/4 cup) White school glue may not work. You will mix glue and water in equal parts. Note that you’ll need more glue for Part 2.
Toothpicks 10 80
Press ’n Seal 1 sheet 16 sheets You can substitute sheet protectors if you have them.
Prepared straws 7 56 Each of these is half a straw, prepared as described in Step 4. Each pair of students needs a straw for the water cup. Groups of 4 will share straws for other cups.
Paper towels 2 32 Note that you may need more paper towels for Part 2.
Newspaper Enough to cover a table Enough to cover 8 tables
Small cups 6 48 These cups are used for supplies that are shared when working with another team. We used 3-ounce plastic bathroom cups. If you use paper cups, be aware that vinegar will leak through some brands after an hour and a half. Plan accordingly. Note that you’ll need more cups for Part 2.

Supplies for Part 2 (Making Goo)

Supply Quantity for 1 Pair or Individual Quantity for 16 Pairs Working at 8 Tables Notes
Borax powder 2 tsp 12 tsp Borax is used in Part 1 and Part 2. The total for 32 students doing both parts is 14 tsp (about 1/3 cup).
Elmer’s multipurpose glue 1 Tbsp 16 ounces White glue is used in Part 1 and Part 2. The total for 32 students doing both parts is 20 ounces.
Small cups 4 (two for each experimenter) 64 (two for each experimenter) Small cups are used in Part 1 and Part 2. The total number for 32 students doing both parts is 112 cups.
Paper plates 2 32
Ziplock baggies 2 32
Paper towels (optional) 2 32

Step 3: Mix your solutions before class

To make the baking-soda solution, mix 1 cup water and 1 tsp baking soda in the one-pint bottle.

To make the glue mixture, mix equal amounts of glue and water in your mixing jar or bowl.

To make the borax solution for Part 1 of the activity (for up to 32 students), mix 2 tsp borax powder with 1 cup of warm water. It is okay if all of the borax powder doesn't dissolve.

To make the borax solution for Part 2 of the activity (for a class of 32), mix 12 tsp of borax with 6 cups of water in a half-gallon bottle. If you have just a few students, you can use your leftover borax solution from Part 1.

Step 4: Prepare and set up your supplies before class

To prepare the straws, follow these steps:

  • Cut each straw in half (Note: Long straws may cause small cups to tip over).
  • Lay the straws side by side with their ends squared up.
  • Eyeball ½ inch and draw a line with your permanent marker across the straws, as shown below.

straw setup

To prepare the testing supply cups, follow these steps

  • Count out 6 cups for each group doing the activity.
  • Use a permanent marker to mark cups for each group.
    • W for Water
    • S for Baking Soda solution
    • B for Borax solution
    • G for Glue/water mixture
    • V for Vinegar
    • M for Milk
  • Put 1 Tbsp of the supply in each cup.

To make Mystery Goo in Part 2, each student will also need:

  • 2 Tbsp of glue/water mixture in a small cup
  • 1 Tbsp of borax solution in a small cup


Borax, while safe when diluted, can be a mild skin irritant to some people, especially those with sensitive skin. If you are concerned, you may want to consider having your students wear gloves or use one of the alternative recipes here .

Mystery 5: Gases & Particulate Nature of Matter

Bag of Bubbles

This mystery includes two activities: a baking soda explosion in a plastic bag (carefully designed to avoid a mess), and a hands-on model that helps students understand why the plastic bag explodes.

Students will work in pairs for the first activity, and in groups of four for the second activity. Students working alone will need a partner for the first activity, and a few friends to help with the second activity.

Step 1: Gather supplies

To prepare supplies, you’ll need:

  • a ¼-cup measure
  • a plastic cup or container to hold the vinegar for each table of students (see Step 2)
  • a plastic or paper cup to hold the baking soda for each table of students (see Step 2)
  • paper towels for cleanup

Each student will need:

  • a ziplock snack bag, like this. (Use snack bags rather than sandwich bags. Sandwich bags need more vinegar and baking soda, and the resulting explosion is likely to overflow the plastic plate.)
  • a small paper cup (3-ounce bathroom cups, also known as Dixie cups, work well)
  • scissors

Each pair of students will need:

  • a plastic plate like these, or a large, sturdy paper plate (Note: You can wash and reuse plastic plates for future activities)
  • at least ¼ cup of vinegar (1 quart for a class of 32)
  • at least ¼ cup of baking soda (about 1½ pounds for a class of 32)
  • 2 plastic spoons, each holding about 1 teaspoon (students will use one for measuring vinegar, and the other for measuring baking soda)

Step 2: Print worksheets and prepare supplies

Print out:

For each table of four students (two pairs), prepare:

  • a container holding ½ cup of vinegar
  • a container holding ½ cup of baking soda