chapter 5
SQUASH
IT
Some candies break. Some candies stretch. And some just smoosh.
In this chapter, you’ll discover different kinds of candies you can squash and what happens when you do. Learn how to shrink marshmallows without touching them, why you can stretch some kinds of candy into long snakes, and what kind of candy makes sparks when you smash it. Squash away!
Time: 5 minutes
Skill Level: Medium
Can you squash marshmallows without touching them?
What you need:
Baby soda bottle test tube (available at amazon.com) or
a small clean plastic soda or water bottle
Mini marshmallows
Fizz-Keeper pump
(available at amazon.com)
Rubber band
What to do:
1 Fill the test tube or bottle with mini marshmallows.
2 Screw the Fizz-Keeper onto the top.
3 If using a bottle, wrap the rubber band around the bottle and slide it to be level with the top of the marshmallows. This will mark the marshmallows’ normal size.
4 Push the Fizz-Keeper handle to pump air into the bottle. As you pump, you’ll see the marshmallows shrink.
5 Unscrew the Fizz-Keeper and watch the marshmallows pop back to their original size.
What’s happening:
A marshmallow is shaped by air. Air bubbles inside the marshmallow push out, making it puffy. Air outside the marshmallow pushes in. The push of the air is called “air pressure.”
When you pump the bottle, you’re adding air to the bottle. This increases the air pressure. The air pushes harder against the marshmallows, shrinking the air bubbles inside.
When you unscrew the lid, the air inside the marshmallows pushes out, expanding them back to their original size.
Marshmallows shrink when air is pumped into this test tube.
Time: 15 minutes
Skill Level: Medium
Can you squash a marshmallow with water?
What you need:
1 large marshmallow or several small marshmallows
Waxed paper or parchment paper
Small empty soda bottle
with the cap
Water
What to do:
1 Wrap the large marshmallow tightly in a piece of waxed paper or parchment paper. Slide the paper into the bottle, holding tight to the corner. Shake the marshmallow into the bottle and pull the paper out. Alternatively, put several small marshmallows into the bottle.
2 Fill the bottle with water to the very top and screw on the cap. (Try not to leave any air bubbles.)
3 Squeeze the bottle. Do you see the marshmallow shrink?
What’s happening:
When you squeeze the bottle, you’re applying pressure. The pressure squeezes the air bubbles in the marshmallow, making the marshmallow smaller. When you release the bottle, the air bubbles push the marshmallow back to its normal size.
Squeezing this bottle of water shrinks the marshmallows inside.
more fun
If you leave the marshmallow in the bottle for several days, it will dissolve, and you’ll see bubbles. Where do you think they came from?
Time: 5 to 10 minutes
Skill Level: Easy
You can roll play dough into long, stretchy snakes. Can you do it with candy?
What you need:
Soft chewy candy, such as taffy, Laffy Taffy, or Tootsie Rolls
Cutting board or other surface for rolling
Butter (optional)
What to do:
1 If the taffy is hard, roll it between your palms to
soften it.
2 Put the taffy on the cutting board, press down, and start to roll. (You may want to butter your hands to keep the candy from sticking.) As you roll, move your hands apart to stretch the candy out. How long can you make your stretchy snake?
What’s happening:
Taffy contains a lot of sugar and a little bit of water. Sugar and water stick together. The molecules are attracted to each other, which makes them hard to pull apart. But water can also act as a lubricant between the sugar molecules. This means it helps the molecules slide apart more easily. So, if the candy has the right mix of sugar and water, and if the sugar molecules are not locked into crystals, the candy can stretch.
The sugar and water in this taffy help it stretch.
Time: 5 minutes
Skill Level: Get a grown-up
Can you break your candy like a rock?
What you need:
Werther’s butterscotch candy, striped starlight mints, Jolly Ranchers, or other hard, glassy candy
A way to smash candy, such as a sidewalk and a rock or hammer, or a cutting board and a marble rolling pin
What to do:
1 Smash the butterscotch candy so that it cracks into two or more pieces. Ways to smash your candy (ask a grown-up for help):
• Set it down on a sidewalk and hit it with a rock.
• Put it on pavement and tap it gently with a hammer.
• Put it on a cutting board and tap it with a marble rolling pin.
2 Look for curved surfaces along the break lines. These scooped-out shapes might look like the surfaces of seashells.
What’s happening:
In butterscotch candy, the sugar molecules haven’t formed crystals. Instead, they’re all jumbled together. This kind of substance is called a “glass.” Window glass is also made from a jumble of molecules.
When you break certain kinds of crystals, the breaks follow the lines of the crystal structure. But when you break a glass, the force can go in any direction. This can cause the glass to break with curved edges. Sometimes shock waves traveling through the glass even leave small ripples on the broken surface. You might see these ripples in your broken candy.
Glassy rocks also break with curved edges. One of these rocks is obsidian, a glassy rock formed when hot lava cools quickly. Geologists (scientists who study rocks) look at broken edges when they are trying to identify different kinds of rocks.
The curving breaks in glassy candy are called conchoidal fractures.
Curved breaks in butterscotch candy and obsidian rock.
Time: 5 minutes
Skill Level: Easy or Medium
Can you make Life Savers spark in the dark?
What you need:
Dark room with a mirror
Wintergreen Life Savers
Mortar and pestle (optional)
Baking sheet (optional)
What to do:
Chewing method (easy):
1 Stand in the dark room facing the mirror. (If you don’t have a mirror, get a partner so you can watch each other.)
2 Chew a Life Saver with your mouth open.
3 Look for flashes of light.
Mortar and pestle method (medium):
1 Put the mortar and pestle on the baking sheet.
2 Take the baking sheet and Life Savers into the dark room. (You can leave the light on.) Lay the baking sheet on the floor, on a counter, or on your lap. The baking sheet will help catch crumbs.
3 Put the Life Savers in the mortar.
4 Turn off the light.
5 Smash the Life Savers with the mortar and pestle, and look for flashes of light. (Save the smashed candy for Candy Crystals.)
What’s happening:
When you crunch the candy, electrons in the sugar crystals are separated from the molecules. When the electrons recombine with the molecules, they emit light.
Table sugar also emits light when the crystals are broken, but much of that light is ultraviolet, which we can’t see. Wintergreen oil absorbs that light and re-emits it in a visible frequency. That’s why wintergreen Life Savers give off so much more light than sugar cubes.
Smashing wintergreen Life Savers makes sparks in the dark.
more fun
This experiment works because wintergreen Life Savers contain sugar crystals and wintergreen oil. See if you can make lights with any other kinds of wintergreen candy, such as Altoids. (Sugar-free mints won’t work.)
