Did you know that we use chemistry every single day? Chemistry is the study of matter, and how it behaves. Everything is made of matter! Chemistry explores what things are made of (composition), how things are put together (structure), and how things can transform (reactions). The kitchen is an area of our everyday lives where chemistry plays a huge role. So, let’s roll up our sleeves, put on our aprons, and perform some chemistry!
1. Microwave a marshmallow!
Several things happen chemically within a marshmallow when it is microwaved. The changes are thermal, physical, and chemical. The microwave radiation heats molecules within the marshmallow. This heating causes a physical change to the gas molecules that exist within the air pockets in a marshmallow. Gases expand when they heat. The marshmallow also undergoes a chemical change as the sugar molecules break down because of the heat.
You will need a microwave, marshmallows, and a microwave-safe plate.
Instructions:
- Place the marshmallow on the plate.
- Microwave the marshmallow for a short period of time (15-30 seconds).
- Observe what the marshmallow does.
- Let the marshmallow cool and observe what happens.
What happened when you microwaved the marshmallow? How do you think the structure of the marshmallow played a role in what happened as the marshmallow was heated? What happened to the marshmallow as it cooled? Do you think that change is reversible or permanent?
2. Make “Science Lemonade.”
This experiment, and the next one, explore acids and bases. Acids and bases are chemical substances with opposing properties. The pH scale measures how acidic or basic (alkaline) a substance is. The pH scale ranges from 0 to 14. Acids fall below 7 on the scale and bases have a pH of greater than 7. Neutral substances, like water, have a pH of 7.
A pH indicator is a substance that changes color in reaction to a basic or acidic substance.
You will need 100% grape juice, lemon juice, a couple of clear cups, and baking soda (optional).
Instructions:
- Fill each cup approximately halfway with grape juice. One cup will be used for the control (you will not add or change anything to it).
- Add a few drops of lemon juice to one of the cups.
- Observe what happens.
- Continue to add lemon juice, small amounts at a time. Compare to the control cup.
- At this point, you may taste your science lemonade, if you wish!
- (Optional) Add a small amount of baking soda to the cup containing the lemon juice. Continue to observe what happens. Compare to the control cup.
What did you notice happening to the grape juice as the lemon juice was added to it? Did you get a chance to add baking soda as well? What happened then? Taste the lemon juice. What does it taste like? Acids – when we can eat them – generally taste sour. What type of substance do you think baking soda is?
3. Write a secret message!
This is another fun experiment with a pH indicator and can also prepare young scientists for a future career as a secret agent!
What you will need:
- A table covering (painter’s plastic or newspaper)
- Water
- Baking soda
- Turmeric
- Rubbing alcohol
- Paper
- Small paintbrush or cotton swab
- Larger paintbrush or sponge
- (2) Small bowls for mixing
- Measuring spoons
Instructions:
- Mix a tablespoon of baking soda with half a cup of water.
- Dip the cotton swab or small paintbrush in the baking soda solution and use it to write a secret message or draw a secret picture on the paper.
- Allow the paper to dry.
- Using a new bowl, mix a teaspoon of turmeric into half a cup of rubbing alcohol. Turmeric will stain! Be careful, use a table covering, and consider wearing gloves and an apron.
- Once the paper has fully dried, paint the turmeric solution onto the paper using the sponge or large paintbrush.
- Observe what happens to the paper and your message.
Take a moment to rub some of the baking soda solution between your fingers? What does it feel like? Did you know that feeling slippery is a common property of basic substances? What did the paper look like after it had dried? Could you read the message? What did you see happen when you painted the turmeric solution onto the paper?
Turmeric acts as a pH indicator because it contains a natural compound that changes color in the presence of acids and bases. How might you test if a new substance could be used as a pH indicator?
4. Take a raisin out dancing!
The disciplines of science are often interconnected, and this experiment is fun because it touches on chemistry as well as physics concepts. It is also fun because we get to make raisins dance, and who doesn’t love to dance?
What you will need:
- A clear cup, glass, or jar
- Warm water
- A few teaspoons of baking soda
- A few teaspoons of vinegar
- Raisins
Instructions:
- Fill the glass half full of warm water.
- Add a few teaspoons of baking soda.
- Add a few raisins. Observe.
- Add a small amount of vinegar.
- Observe what happens.
What happened when you first added the raisins to the cup of baking soda and water? Did the raisins sink? Then, when you added the vinegar, what began to occur? Were bubbles created? When baking soda and vinegar combine, they create a gas called carbon dioxide. Why does the gas rise to the top of the water? Did the raisins catch a ride to the surface with the carbon dioxide bubbles? What happened to the raisins when they reached the surface? Do you think other items may behave similarly? Why do you think raisins attach to the gas particles so well?
5. Have an edible gelation ball
Gelatin is made up of a protein called collagen. Gelatin works by creating interconnected protein chains that trap water, thus creating a gel. Did you know that collagen is the most abundant protein in the human body, where it also attracts and retains water?
For this experiment, you will need a plate, craft sticks, some flavored gelatin, and drinking water.
Start by placing some of the gelatin powder on the plate in a small, flattened pile. Add the water drop by drop onto the gelatin. Allow the gelatin and water to rest for a few minutes. Observe what happens. Use your craft stick to lift up the congealed gelatin. Feel it in your hands. Eat it, if you wish (as long as your hands are clean)!
What did you notice? What was the texture of the gelatin like after you added the water and allowed it to rest? Is it a solid or a liquid? How do you think gelatin balls may be like some of the matter in our own bodies?
Did you find these experiments fun?
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