《声音》 VOICES Ivy's VOICES Spring/Summer Edition 2019 | Page 33

SCIENCE CORNER The Shenanigans Behind the Putty: Elmer’s Glue is a mixture of long PVA( poly vinyl alcohol) molecules and water. All of the molecules attract to each other with hydrogen bonds (dipole-dipole force). The water helps lubricate the PVA molecules and keeps them sliding around by each other. When you add the cross linker in this case liquid starch the glue takes on a rubbery, stretchy and slimy glob of fun. *Note: Please note that this substance is exciting to play with but, there are some precautions to take. Children should not handle this goo unattended as it can get into hair (NO FUN) or in clothing. If it does find its way into hair add soap directly to the goo effected area soak with warm water then gently comb it out , wash hair as usual. If it gets into clothing add hand sanitizer, or dawn dish soap scrape away the excess then wash as usual. Extension Activities: Teachable Moments If you have access to store bought Silly Putty, Gak or Slime ask children if they think they can guess what the gooey substances are. Show them what the goo can do and encourage them to explore and experiment with them. If you do not have access whip up a batch and allow them to explore with it. After children had time to explore with the goo’s, ask them open-ended questions i.e. “ What do you think this stuff is called?”, “Do you think we can make our own goo?” etc. You and your child can create your own recipe chart. Draw out and write down the recipe breaking it down into simple directions. Your child/children will be proud when you display their recipe for all to see. 1. Use clear glue in place of the white glue, add glitter and place in plastic eggs usually found around Easter time or online. They make great party favors or stocking stuffers. 2. Wad up a large marble sized wad of goo and place on the end of a straw. Make certain to create a seal between the goo and straw and blow! Wow, did you see what happened? Yes you just witnessed how stretchy and pliable this goo really is. You blew a bubble. 3. You can use play dough toys and scissors while playing with the goo. 4. A popular goo like substance most people make is made with cornstarch and water. Dump a box of cornstarch on a tray, provide eyedroppers and water encourage children to add water to the starch until it is a substance which can be picked up in chunks and then melts in your hands. Fancy words to look up: • Polymer • Cross linker • Poly vinyl alcohol The Twist : Make a timer using a clean and empty 20 ounce bottle with cap, a hammer and screwdriver and a batch of nutty putty goo. Punch a hole into the cap with the screwdriver and hammer, lay the cap on a flat surface put the screwdriver in the center of the cap and give it a good whack with the hammer, TADA a hole. Break the goo into bits so it will fit it the bottle with fighting with it. Once the bits meld together, tip the bottle upside down allowing the goo to flow out of the bottle and into a bowl , time how long it takes all of the goo to flow. If it took 10 minutes well you have a 10 minute timer. Make a timer holder, my students tape the timers to the back of a chair and place a bowl underneath the timer. 31