Question: Ask the children, “what are the 3 states of matter ?”
Answer: Solid, Liquid, & Gas. Put Solid Liquid & Gas cards up on the poster.
Characteristics of Solids (hard/soft sponge, powder, clear, opaque, salt, glass, metal)
Characteristics of Liquids (pour, Honey, Water, Oil, Soap, Alcohol)
Characteristics of Gases (Air, helium in a balloon, bubbles in soda, exhaust from a car)
Solids can be soft or they can be clear, but solids keep their shape. That’s why we say we eat a piece of bread, or a chunk of cheese. But we never say we drink a piece of water, breath a chunk of air. Instead we drink a cup of water or breath some air, because liquids and solids don’t have any shape.
In order to understand Solid, Liquids, and Gases we first need to think about atoms.
Show the box of atoms briefly. Explain that the ping pong balls represent atoms.
Explain that everything is made of Atoms. Atoms are very very small.
Put a cookie on a plate, cut into ½, ¼, 1/8, 1/16, etc… Look with a magnifying glass. Ask the children
how much smaller would we have to go to get to just one atom ?
Measure the thickness of a human hair (Diameter = 2 thousandths of an inch = 500,000 atoms across).
Laptop - show relative sizes: Dust Mite, Bacteria, Cells, Virus, Atoms.
Question: What is the difference between liquid and gas ? Use the Box of Atoms to show a Solid
(neighbors stay next to each other), Liquids: the atoms roll over each other. Liquids can pour like orange
juice into a cup. Can you pour a solid ? No. Finally show a gas. The atoms bounce around violently.
Notice that a gas takes up more space than a liquid does. Compare the density of each.
Question: How can we change a Solid to a Liquid to a Gas ??
Question: First let’s think of something that comes in all 3 forms ? Ans: ice, water, & steam.
Have each child hold a piece of ice in their hand. What happens to the ice ? It melts. We add Heat. Heat
is just atoms moving around in every direction. Heat is a form of Energy. Show the box of Atoms again.
Introduce Temperature. Hands in 3 water paths, cold, warm, hot. Children read the thermometers in each.
Show poster of a big Thermometer & Ref Temperatures (Venus 800◦F, Boil water 212◦F, comfortable 72◦F,
Ice freezes at 32◦F, Antartica approx -100◦F).
Optional: for the older children. Approximation to convert from temperature in Celsius to Farenheight.
TF 2 x TC + 30. Plug in TF = 0, 20, 100. Compare with the exact results using: TF = 5/9 x TC + 32.
Show the steam source. Water changes into steam, and then steam condenses back into water.
Question the children and add these words to the poster.
Boil water (Liquid to Gas)
Vaporize (Liquid to Gas)
Condense the steam back into water (Gas to Liquid).
Melt ice (Solid to Liquid)
Freeze or Solidify (Liquid into Solid)
Optional: For older children explain “conservation of mass”. Mass is conserved in Transformations from solid to Liquid to gas. But Mass is also conserved in chemical reactions. (not here).
Example: Where does a Log go when it burns in a fire ?
Can anything change from Solid to Liquid, to Gas ?
Can a metal melt ? Can a metal turn into gas ?
Show that Torch melts metal solder.
Now let’s go to the cold end of the scale
Pour some Liquid Nitrogen into a metal bowl.
Poster of Thermometer. Unroll to show LN2 is -320 deg F
Freeze a balloon in Liquid Nitrogen (air condensed into a liquid). Show the liquid in the bottom. Lift the
balloon out with metal tongs. Balloon expands back to full size as it warms (Liquid back to Gas)
Question: What would happen if we freeze our finger ?
Freeze a hot dog, sponge, flower, rubber ball, and a racquet ball.
Show liquid Nitrogen boils in a pan.
Nailing contest with a frozen banana.
Throw a frozen racquet ball. It smashes into pieces.
Equipment needed
4 tables (2 tables in front of me, plus 1 table on each side of me)
Marker Board & markers
Safety glasses for all the children.
Solids; wood, metal, plastic, glass, salt, cotton balls, plastic wrap, baby powder
Liquids: water, oil, honey
Cookie on a plate w/ knife & Magnifying Glass.
Laptop with Size comparison Bacteria, Cells, Virus, Atoms
Notebook of pictures Bacteria, Virus, Atoms...
Atoms in a box
Poster of Solid, Liquid, Gas, Melt, Boil, Condense, Freeze.
Cooler full of ice, & a bowl for ice.
Poster of a Thermometer, (rolls out), velcro.
3 plastic boxes + 3 thermometers for water baths.
Coffee maker (a source of hot water).
Extension cord, Power strip
Steam source: Ring stand, clamp, flask, rubber stopper, glass tube
Bunsen burner, Propane tank, Gas regulator valve & gas hose. Spark igniter
Condenser: Plastic box for ice bath, copper tubing, clear rubber tubes,
Calipers to measure a human hair.
Solder & soldering gun (heavy metal can to put soldering Iron into).
Cryo-gloves, & Tongs
Metal bowl & Block of styrofoam for LN2
Hammer, 2 Boards, Nails, C-clamp
Consumables
Liquid Nitrogen in a Dewar
Balloons, hot dogs, bananas, flowers, super ball, Racquet balls, Ice
Access to hot water
Where to buy Liquid Nitrogen and the Dewar
Liquid Nitrogen Dewars are very expensive, but you can rent one at:
Polar Cryogenics Inc.
2734 SE Raymond street (near 26th & Holgate)
in Portland Oregon
503-239-5252
10 Liters of LN2 $40.00
Dewar rental $25.00
Total $65.00
What are the 3 states of Matter ?
Poster (Solid, Liquid, Gas)
Characteristics of Solids, Liquids, Gases
Atoms
Show the Box of Atoms Briefly
Cookie
Human hair (500,000 atoms diameter)
Laptop (Dust Mite, Bacteria, Virus, Atoms)
Solid Liquid & Gas
What is the difference between Liquid & Gas ?
Box of Atoms to show the differences between Solid, Liquid, & Gas.
Gas takes up more space than liquid
Heat
How can we change Solid Liquid Gas ?
What comes in all 3 forms ? (Ice,Water Steam).
Ice in hands
Explain Heat
Temperature
Hands in water
Thermometer Poster (Venus 800ºF Boil 212ºF, comfortable 70ºF, ice 32ºF)
Older kids: TF = (2 x TC) + 30
Safety Glasses
Steam Source
Poster add: Melt, Boil, Condense, Solidify
Older kids: Conservation of Mass
Example: A Log in a Fire. Where does it go ?
Liquid Nitrogen
Now let’s go colder
Unroll - Thermometer Poster
Liquid Nitrogen - Balloon / Hot Dog / Sponge / Rubber ball / Banana
- Boil LN2