Science of GLOW!

Every week, Madison (my 10-year old daughter) and I teach a 1.5-hour afterschool science club for K-2nd graders.  Each week she helps plan the lesson and then write the blog about what we did.  Then I add my 5 cents worth and we post the blog.

We have provided links to the books we used to sneak in some literacy.  We learned most of the science experiments and activities from Steve Spangler (awesome speaker and science guy extraordinaire).  We have included links to his science supplies, experiments, and videos.  We have also included links to our YouTube video science lessons. These links take you away from the blog and to external websites.

Lesson 13

Science of Glow

See our YouTube video on the Science of GLOW!

Science Standards Addressed:

• Knows that light is a form of energy, Recognize that energy can be stored in many ways (phosphorescence).
• Know that changes to matter may be chemical or physical and when two or more substances are combined, a new substance may be formed with properties that are different from those of the original substance.
• Know that materials are made up of small particles that are too small to see with the naked eye (monomer and polymer science).
• Know that bacteria and viruses are germs that affect the human body. Describe ways to prevent the spread of germs.

Plus we snuck in some speaking and listening standards like asking questions, expressing ideas, following multi-step directions, and participating in discussions.

As the children arrived we played the songs When the Lights Go Down in the City, by Journey; and Party Lights, by Claudine Clark.

10 Minutes

Simulated Germs

As the children arrived, we pumped a little glob of Simulated Glow Germs on their hands.  We asked them to rub the “lotion” into their hands making sure to get the backs of their palms and fingernails.  Then we asked them to wash their hands the way they normally do before eating snack.  Then, we put their hands back under a black light.

You could see glowing “germs” all over their hands – especially in between their fingers and in their finger nails.  We taught them how to wash their hands: by scrubbing EVERY surface of their hands for the same amount of time it takes them to sing Happy Birthday to themselves FOUR times!

Then we put their hands under the black light again.  It was much better this time, but there were still some germs that did not get scrubbed away.  After one more round of hand washing, no more Glow Germ showed up, and we mercifully let them eat snack.

5 minutes

Snack

Our snack was an extra cool hint of the science to follow. 

In addition to the healthy stuff, we snacked on GLOWING gummy worms

 (don’t be alarmed, only the forceps glowed – and the light shined THROUGH the worm).

10 Minutes

Literacy Connection

To sneak in some literacy standards, while they ate snack we read them

The Very Lonely Firefly, by Eric Carl

 - a book about a lonely firefly who wants company. He fly’s around and every time he sees a light he goes to it, thinking it might be a firefly, but it always turns out to be a lantern, light bulb, a candle, flashlight, fireworks etc. One time he sees many lights and they are lots of fireflies! In the book we got the picture of fireflies light up with real lights. COOOL!!

We also read 

Sam and the Firefly, by P. D. Eastman –

a book about two friends Sam who is a firefly and Gus the owl. Gus likes to play tricks on people. He would write words in the sky. The words would tell planes to go up or down, left or right and the planes would crash. He would do that to cars too. Just then an angry man caught him. The car of the angry man broke down on the railroad tracks. A train was coming and was going to crush the car so Sam rescued Gus and Gus wrote the words STOP, STOP, STOP, STOP! And the train stopped just in time.

5 minutes

Black Lights

We taught them a little about how black lights work.  They are the lights that make your teeth, white clothes, and fluorescent things glow in the dark.

 When you turn one on, you see the visible purplish light, but you don’t see the invisible untraviolight light also being produced.  The energy in UV light excites the phosphors in fluorescent materials, which convert it back into visible light, emitting cool colors.

20 Minutes

Glow-in-the-Dark Paper

We all knew about incandescence  - producing light from heat like in an incandescent light bulb, candle light, or the sun.  Today was all about exploring light made by means other than heating = luminescence!  Both forms involve exciting electrons that absorb energy and jump to an outer orbit and then release photons when they drop back to a lower orbit.

We explored sheets of glow paper using some mini black lights that we let the kids take home. 

We traced our handprints with these lights, and removed our hands to 

see cool green glowing handprints.  

We also snuck in some literacy by writing our names and secret messages
on the glow paper with our lights. 

Substances like this that “Glow in the Dark” produce a luminescence known as phosphorescence. Sometimes clocks or emergency exits are highlighted with phosphors (which absorb energy over some period of time and then give off light for a longer period of time).  Zinc Sulfide is the phosphor embedded in this glow paper.

20 Minutes

Atomic Slime

We mixed 2 ounces of the Atomic Slime solution (poly vinyl alcohol – PVA)

with a spoonful of the cross-linking (borax) solution into the handy dandy shaker cup and did the Shake Shake Shake, Shake Shake Shake, Shake your Atomic Slime dance.

Atomic Slime and Atomic Worms contain a special coloring agent that fluoresces under black light. When the energy from the black light “excites” the fluorescent dye,
you end up with a brightly glowing and very cool substance!

We told them that all matter is made up of things to small to see with our eyes – atoms and molecules.  In most liquids single molecules (monomers) bounce around – not connected to each other. These liquids flow easy (little viscosity) aren’t slimey. In this case, monomers are linked together in long chains – polymers.

We showed the kids a model we made.  It is a pile of chains of various lengths.  We explain that these chains are a little like polymers.  If we grab one, only a single chain comes loose.  Then we add a bunch of magnets and mix everything up.  Then we show the kids that NOW if we grab a chain, we get a blob of chains all stuck together.  They have been CROSS-LINKED – chemically – not magnetically.

Atomic Worms

Finally, we whipped up a batch of worms. In a similar demonstration of cross-linking, we squeezed squirts of atomic worm goo into the worm-goo activator (borax) solution.

The Atomic Worm Goo is a polymer, and the Activator, cross links the solution so that the goo immediately changes from a liquid to a solid!

 This kind of luminescence is known as fluorescence.  Fluorescent materials STOP emitting lights almost immediately after the exciting energy is cut off.  Fluorescent dyes are included in many clothes to make them appear brighter.  Most organic materials fluoresce under UV light, so we can detect biological materials and fingerprints using UV light.

Light can also be produced by other processes in which heat is not involved.

For example, fireflies produce light by means of chemical reactions that
take place within their bodies – bioluminescence.

Glowing light sticks produce light through a chemical reaction – chemiluminescence.  

In many flat panel displays, electric currents are passed through a material that glows – electroluminescence.