OUTREACH : 50-min. HANDS-ON WORKSHOPS : Chemistry

Awaken the chemist in you. Explore states of matter and what happens when you go between them. Learn the difference between a physical and a chemical change.

Michigan Grade Level Content Expectations, Science, 2007

Chemistry Pre-visit Vocabulary

Gas: A state of matter where the molecules are loosely packed, taking up the entire space of their container.

Liquid: A state of matter between solids and gasses where the molecules spread out to take the shape of the bottom of their container.

Solid: A state of matter where all the molecules are tightly packed, resulting in a rigid shape.

Molecule: The smallest particle of any substance that retains the same characteristics.

Acidic: Having a pH less than 7.0.

Basic: Having a pH greater than 7.0.

Chemical Change: A change in the chemical make-up of an object or substance, such as wood burning. Chemical changes cannot be reversed.

Element: A substance of matter than cannot be chemically broken down into a similar substance. These are the basic building blocks of molecules.

Energy: The capacity to do work.

Matter: Anything that has mass and takes up space.

Neutral: Having a pH equal to 7.0.

Periodic Table: A chart showing all of the known elements ordered by their atomic weights.

pH Scale: A measure of the acidity or alkalinity (how basic) of a substance. pH stands for the “potential of Hydrogen”.

Physical Change: A change in the physical structure of an object or substance, such as ice melting to liquid water. Physical changes can readily be reversed.

States of Matter: The physical arrangement of molecules in a substance or object. There are three main states of matter.

Surface Tension: The tendency of molecules to stick to or adhere to other molecules on the surface of a liquid, resulting in a pseudo-skin.

Vibration: Rapid back-and-forth movement of molecules.

Chemistry Post-visit Activity

Post-visit activities provide your students with an opportunity to review workshop-presented concepts and introduce related subjects. Below you will find a classroom extension activity and a list of suggested resources for further exploration. We hope that you enjoyed our Outreach Hands-On Workshop and we look forward to visiting your students again!

Hands-on Activity: Floating Bubbles

Materials

• 1 large, clear container (like an empty aquarium)
• 1 cup of vinegar
• ½ cup of baking soda
• Bubble solution
• Bubble wand
• Empty bowl

Procedure

1. Place the aquarium in a still area.
2. Place the empty bowl inside the aquarium.
3. Pour the baking soda into the bowl.
4. Pour the vinegar into the baking soda. You’ll notice it immediately begins to fizz.
5. Allow the solution to fizzle out for a few minutes.
6. Slowly blow a few bubbles into the fish tank. Be careful to not blow directly into the tank.
7. Observe your bubbles.

Discussion

Most everyone has, or will have, made a volcano at some point. The two main ingredients are the same as in this one. The vinegar and baking soda undergo a chemical change when mixed together, releasing carbon dioxide. Carbon dioxide, or CO₂, is denser (heavier) than regular air. The aquarium traps the CO₂, not allowing it to spread out in the room. The bubbles are full of air. They float on the invisible barrier between levels because they are less dense than the CO₂.

A variation of this experiment can be done with dry ice. Using dry ice also allows you to discuss the process called sublimation, a process during which a substance goes straight from a solid to a gas. Carefully (it is cold), place a few chunks of dry ice in the bottom of your aquarium loosely cover the lid for about an hour. It’s important to not create a seal because pressure will build up quickly. After a while, you should be able to blow bubbles onto the surface of this CO₂ layer. You can see this at work on a sunny day with lots of snow.

Suggested Resources

Books

VanCleave, Janice. Janice VanCleave’s Chemistry for Every Kid: 101 Easy Experiments that Really Work. Wiley. 1989.
Newmark, Ann and Laura Buller. Chemistry. DK Children. 2005.
Cooper, Christopher. Eyewitness: Matter. DK Children. 1999.
Rohrig, Brian. 150 Captivating Chemistry Experiments Using Household Substances. FizzBang Science. 2002.

Internet

Rader’s CHEM4KIDS
Water Experiments
States of Matter
Elementary Science: Matter