Chromatography and Gravity

Chromatography: Is Black Marker Really Black?

The very important scientific technique of chromatography (separation of colors or parts in a mixture) can easily be introduced to kids by testing whether black is it's own color, or a combination of many.

1. Cut strips of either coffee filters or paper towels (I used both)
2. Have kids draw a line with a black washable/non-permanent marker. I used crayola. Make sure the line is at least a little higher up than the edge.
3. Place strip in water. Make sure you do not immediately submerge the marker line.
4. Watch as the water is absorbed and travels up the paper. What happens when it reaches the marker? The colors begin to separate. The color black is actually a combination of many colors (ROYGBIV). These colors travel up the paper at different speeds. With our markers, the separation of blue and red was clearly visible, with red moving further up the paper than blue.

Depending on age and curiosity of kids, you can go deeper into explaining this process, why it happens, and what it is used for in science and forensics. Talk about chromatography paper and other professional equipment. Usually other solvents are used instead of water, like rubbing alcohol or other liquid chemicals.. many of which would probably produce better results than our run. Or keep it simple- black is actually a mixture of many colors and an simple experiment can prove that to us. I also used a "mystery ink" which nothing happened to when placed in water... I had kids compare and deduce why. Some thought it was a different paper or water or technique, but eventually (and some quicker than others) realized this was a permanent marker and the markers we used were water-based.

Few tips:

• water travels up paper towels faster than coffee filter, obviously. Keep that in mind for impatient kids
• If you dunk the marker line into the water immediately, the experiment won't work. Boys especially didn't listen to directions and did this on their first try (see some in 2nd photo below)
• The steadier and still and longer you hold your paper upright in the water, the better results and better separation of colors you will get.
• If for some reason the water is taking a long time to reach the marker (most likely because a child put it too far up) you can help it along... don't submerge the line, but slowly dip the strip further into the water to speed up the process.

              

Gravity

I did a few simple gravity demonstrations. First, I asked my kids if they could explain to me what happens when a ball is thrown up in the air. Why does it fall to the ground? Why do all things we throw fall to the ground? Is there a name for this process? Is there anywhere we don't experience gravity?

Then I used simple items: book, feather, piece of computer paper (flat), crumpled up paper, small ball..etc to test which items fall faster to the floor and why? (weight and/or surface area)

Second experiment was learning how water travels from high places to low places because of gravity. We learned about a special tool, a siphon. When filled with water completely, you can place one end of the siphon in a bucket of water and the other end in an empty bucket of water (at a lower elevation than the full bucket).  Water will move from the full bucket into the empty bucket. We don't have our fish tanks yet but I spent time explaining that the siphon is used often during water changes for very large tanks- it is much easier than scooping water out!

Having two cups or buckets of the same size would be much easier. When the cup at the bottom was full of water, we stopped each end of the siphon simultaneously (by putting our thumb over it). Then we either poured out the bottom bucket or switched the places of the two buckets. Then put the siphon back into position and released our fingers. If the siphon is not completely filled with water at all times the process won't work and you'll have to stop and refill the siphon. The end that is pulling the water needs to be submerged in the water the whole time. At the other end, we held it a little above the cup so that everyone could see the water coming out.

                         

Density Experiments

I am beginning a week entirely devoted to hands-on experiments involving Chemistry, Physics, and Biology.

To start the week, we explored density by making a liquid rainbow using salt, water and food coloring. 

Getting the ratio of salt to water right IS KEY!!!

I looked up a couple directions online and did a test run at home first. The first picture is what I was able to accomplish with the following proportions:

• ALL: ~9 oz water
• Blue water: 4 TEASPOONS salt
• Green: 3 teaspoons
• Yellow: 2 teaspoons
• Red: 1 teaspoon

( you could modify the salt so that there is barely any or none in the last one... since freshwater floats about salt water)

Using a pipette, collect the most dense color first (blue). The more salt added, the heavier the solution gets, thus more dense than regular water.

VERY slowly squeeze water out into your cup or beaker. As you add the other colored layers on top it is important to :

a) squeeze slowly and carefully

b) do so very close the water's surface and along the side of the cup AND angling the pipette helps as well.

We had 4 oz beaker cups, so my instructions for the kids were a ounce of each color (fill blue up to 1, green up to 2, yellow 3.. etc)

Getting the salt ratio right is sometimes trial and error. The first round I didn't have my note sheet with me and messed up the amount of salt I put in... and it made a very visible difference. 1-2 kids who were very patient and careful were able to get about 2 different visible layers. After I reconfirmed the amount of salt to water, we all did a second trial of the experiment and it worked much better! Kids with lots of patience and focus had a better pipetting technique, resulting in a overall better rainbow. 

This was a great tie-in to discuss the Hudson River and that it is a tidal estuary, meaning it has a mix of salt and freshwater.

This project should be done in a VERY well lit area or close to a window. Even though we were in a big room with several windows... most of the time as the kids were layering their entire cups of water looked very dark against the brown wood tables. Holding right up to the window made the appearance better. My practice run over the weekend was conducted right next to a bright window. Below is what a majority of kid's projects looked like. Even though you can't see on these pictures too well,, we did have some visible blue on the bottom and when held up to the sunlight, some orange/yellow.

Sink or Float?

During snack time I showed everyone two containers. One with a egg sinking in freshwater and one with the egg floating in saltwater. I asked the kids if they could guess why. (obviously because the salt makes the water heavier) And my kids who were participating in the experiment earlier were quick to shout out and not give others time to think... but nonetheless it was a good, quick little demo to give other kids not usually participating in env. programming a taste of what we had been learning today.

Oceans

What Makes up the Ocean?

I started ocean week with some activities to introduce my kids to the variety of species and environments found within the ocean. I had seen someone label the ocean zones using a paint chip, so I took that idea and ran with it a few steps forward. We made a book, with the front a writing opportunity to describe the different zones. Inside we did animals typically found in each zone.

Key talking points:

• why are more animals an vegetation found in the upper most zones?
• what happens to temperature, light and pressure as we move deeper into the ocean?
• what special features to animals living in the midnight zone and abyss have?
• why are coral reefs found in higher zones? (also can discuss the continental shelf)
• why might some animals occasionally move to higher or lower zones? (food)

If I were to do this activity again, I recommend using larger paper. Younger kids tend to need more room to write. My kindergartners also instinctively used the dotted line zone divider as a lines meant for each word.... so we ended up modifying for the really young ones to having one summary sentence on the front such as, Temperature gets colder as you travel deeper. or There is more light in sunlight zone than the abyss.


We reinforced this activity by reading the Disney story, FINDING NEMO! The characters actually travel the many different ocean zones during the movie/story.
Great Barrier Reef- very beginning
Open Ocean- Marlin races after the boat that has Nemo
Twlight/middle zones- meeting the sharks
Abyss- following the mask and getting chased by fish
Trenches- encountering the jellifish
East Australian Current- traveling with the turtles
Harbor- scooped up by the gull

I also just found this awesome Finding Nemo Educator's Guide after the fact. You could probably make a whole week of Nemo themed activities from it...

Parts of a Fish

The fish skeleton and dissection models were definitely a BIG HIT! 

Some kids (especially the boys) spent the entire time looking at these things. The plastic fish model has a couple pieces like the gills, liver, and a few other things are magnetic piece which can be pulled out to see what is underneath or behind. Both models have numbers on all the organs and body parts and kids spent a long time not only identifying the numbered parts but comparing the difference between the "real" fish and the plastic fish parts.

The girls were a little less interested, but were happy to do a fish craft. My emphasis for the day was mostly on understanding at least the basic features and their importance: gills, fins, tail, mouth, eyes, scales. Our craft using old CDs helped them identify all these parts.

A Day at the Beach

To learn about the features and life at the beach we did a few activities, and I had a lot of show and tell items like a starfish; tons of shells including clam, oyster, and snail; blue crab carapace; horseshoe crab carapace; sand dollar; coral.

We made shells prints, or fossils, using Crayola model magic. This is a very simple activity and using model magic was so much easier and less messy than the plaster of paris we used to make animal tracks!

After snack, we did a messier project- crab handprints. I put a little bit of sand in a pan and instructed kids to put glue on the bottom of their pages first (use glue stick), they then drizzled sand and shook off excess, all in the pan. Next they painted their hands, some need help painting the second hand. Also unless you really direct their hands, they might not spread them out wide enough. Even so they all came out looking GREAT!

Ocean Songs
It is so simple to search the internet and find fish and ocean songs. Here's two I love:
The first is a song about Horseshoe Crabs as a part of a conservation initiative called Flip Em Over

The one below is about crabs and was made by someone at the Padilla Bay National Estuarine Research Reserve. I had the pleasure of meeting this awesome guy at a NERRS annual meeting and hearing the song is person!

How are our Oceans Doing? 
Oils Spills and Other Threats 

 To end the week, we did some true environmental education. We talked about different ways humans impact our oceans- oil spills, pollution, overfishing/bycatch, climate change and ocean acidification.

We did an experiment to explore how difficult it is and the option for cleaning up oil spills. I set up 3 aluminum pans with water. To represent crude oil I used a mix of vegetable oil (any cooking oil should do) and mixed with a bit of coca powder to give it the brown oily color. We put a bit of oil in each pan. I provide 3 options for cleaning the spill (hence 3 pans)

1. Dispersant- spray bottle with dishwashing soap/water mixture. Dispersants are chemical sprays used, usually overhead by planes. If done properly (sprayed several times in the same spot), you should see the dispersant breaking up the oil. After a while you'll notice this tray gets lighter in color because the soap is mixing up the stuff.
2. Hard Boom and Skimmer- Use a couple straws (bend and put inside each other) to simulate a hard boom often dragged by a large boat. Gently place the "boom" at the surface of the water and slowly pull it towards you, the oil should be trapped and pulled along with you.
3. Absorbent Boom (soft boom)- I was going to use something like cotton balls, but forgot them. I think paper towels worked better than cotton balls anyways. Roll up the towels. You can have them use the same pulling method as previously but explain that this also absorbs to oil too. Or discuss how these are placed at the shore in anticipation of oil being pushed by waves.

My TEENS participated which made me super happy! They are more critical than kids however, so they felt like none of these techniques were working. Which is okay if the project fails, or didn't work as well as  I had hoped.. it just goes to show how incredibly hard it is to clean up oil spills!

Part 2 was discovering how animals covered in oil are saved and cleaned. I had 3 options set up: cold watet, hot water, and soapy water (dishwashing soap). Students dipped a feather in oil and then tested the 3 options in order. Obviously, the soap should work best... it didn't really do a decent job in my opinion. Some of the younger kids were all excited saying they saw a difference... There's a couple reasons why it may not have worked as well as I expected... ratio of soap/water, types of feathers used (all were real), needed more time to soak.

There are tons of similar oil spill experiments online.. took some of my concepts from this set of 3 videos: Oil Spill Experiments (by Kidsgetaplan)



With many of the young kids we first sat down and read the book Oil Spill! by Melvin Berger. It helped introduce the issue of oil spills- how they occur, who they impact, and how we can clean and prevent them. Then we tackled the experiment, and I often referred back to parts of the story.

I also had some good photo visuals of oil spill clean-up tools, oil covered animals, and other ocean environmental issue visuals... these were more appropriate for older kids.

Plants and Trees

For a massive 2-week theme we explored seeds, flowers, trees and forests.

Games

Tree Nutrient Competition:
From either Project Learning Tree or Project Wild, this game teaches kids what plants need to grow and what happens when trees have to compete for resources.
1. Begin by spreading the kids out, have them imagine they are trees with their roots (feet) planted firmly in the ground. They cannot move their feet in this game.
2. Use colored toothpicks, popsicle sticks or something else small that you have at least 3 colors of to represent the nutrients (sunlight, water, soil) Ask kids first if they can identify the 3 things plants need in order to grow.
3. Sprinkle these on the floor. Be sure to put some of them close to the kids on some of them too far away to reach.
4. Challenge the kids to gather as many resources as they can, WITHOUT moving their feet or touching their knees or butt to the ground. If you have very fidgety kids you could probably use something like a small mat or hula hoops to help the kids conscious of when they move their feet.
5. Repeat activity with all the kids bunched up back to back (and overcrowded forest). What effect does that have on gathering nutrients? Was each child still able to acquire a substantial amount of each resource?
5. If you want to talk about invasive species and tree diseases, you can add a 4th color to the mix without telling kids what it is first. After they have collected, tell them this color represents disease.

Tree Simon Says:
This was a simple on the spot game that stemmed from a quick physical activity to teach kids the parts of the plants and how it grows.
-Everyone starts as a seed, curled up in a ball
-spread your legs out on the ground, the roots begin to grow
-slowly raise your body to represent the steam
-as you get closer to standing up grow a shoot with your arm and then a leaf by opening your hand

After a request to play something different like tag, I changed this to a simon says game (be a seed, grow some roots, sprout a leaf...)

Forest Food Web:
Another simple prep, create forest animal nametags (deer, hawk, worm, etc) on index cards and attach string to each so that they can hang on childrens' necks. Talk about food chains, pyramids, and webs and ask the kids what they think the system most resembles. Is is a single on-way chain? Is it a back-and-forth web? Use a ball of yarn to help document the journey from animal to animal, having each kid hold on to a piece of the yarn to help make the web. Sometimes the yarn might get passed back to the same person (usually lower on the food chain) many times, some might only receive it once.

Buck, Buck, Moose:
This card game has no science education to it, except that you can tie in conversations about moose and rangers (forest rangers help protect forest animals). It's basically a mash-up game between duck, duck, goose and hands down. My very young kids absolutely love it, and it's a good color matching game.

Activities With Leaves

Leaf Rub:
Depending on the season you do this, you might be able to use real leaves. Otherwise there are places you can buy leaf plates which just work just as well or better and is what I used. You place the raised side of the leaf under the paper (if using a real leaf, this is usually the side you can see the veins). Crayons work best, rub slowly and on an angle.
I had a leaf ID poster out so kids could identify the types of leaves they were making.

Microscope:
If you have microscopes, putting a leaf under is always a big hit. At the time, all we had was a very very cheap children's microscope, but young children (especially my city kids who barely know what a microscope is) will be fascinated by it.

Bark Activities

Touch and Feel:
I had a couple show and tell items including a large piece of bark. Talk about the texture and how it relates to the purpose of bark on a tree.

Tree Rings:
Tree rings represent the age of the tree. Have kids draw their own tree rings, that is, if they were a tree how many rings would the have? (the equivalent to their age) Let them use creativity to color code their rings. For example maybe something memorable happened when they were 6 years old- a special birthday, new school, etc. They can choose different colors to represent special milestones. Also, the spacing of rings is important. Trees with rings spread apart means a lot of growth each year. Encourage kids to think about growth spurts they may have had, and illustrate that on their drawing. I used paper and pre-traced the tree diameter for them. I prefer using paper plates.

Seeds

Touch and Feel:
Again, I had some show and tell items, including an incredibly large pine cone and a walnut seed. I also had great visuals to show the different types of seed and methods of dispersal.

Planting:
One day we had an opportunity to plant our own seeds. We created a recording of each flower type every kid planted, so that when the flowers bloom we can remember which ones they are. (Also to help figure out why certain ones might not be growing, i.e. all of one specific seed aren't growing) We planted many on March 10, as of now (March 22) none have begun sprouting. Be mindful of how old your seeds are, I believe the seeds we used are all way too old and the main problem. We also don't get good natural light in this room and I have been struggling to decide how much artificial light is necessary. Lastly the room we have these in is always very dry and humid.

Miscellaneous Forest & Plant Activities

Books About Trees and Gardening:
We utilized a lot of great visuals, posters, and books to learn about the parts of the plant, growing plants and vegetables, and forest and maple sugaring. One of the most helpful items was this interactive activity book, you can use dry-erase marker on the pages. Some pages teach the concepts, other pages reinforce be requiring matching, circling, or numbering. My kids love this book, some now know it inside and out and enjoy taking on the teacher role with other kids!

Maple Sugaring:
It is maple syrup season here on the east coast! I've been running many in-school maple sugaring programs at the park. My after-school kids were going to have a field trip on a half-day to do the maple sugaring class, but do to rain I modified it inside.
-telling a story/legend about the discovery of sap by Native Americans
-tasting sap
-teaching about how and when trees make sap, which trees are the only which the sap produces maple syrup (Sugar Maple)
-how sap is collected and show the tools used through time (wood bucket and spile, metal bucket with lid and spile, plastic tubbing, brace and bit) and how the sap turns into syrup
-real maple syrup vs store syrup taste test

Colored Carnations:

Teach kids where water travels through the plant by taking white carnations and placing in colored water. Put a few drops of food coloring and change water frequently as you would any other vase of flowers. As I kid I did this many times, including for a science fair competition and it worked GREAT. I'm a little disappointed in ours, you could still see the changes and kid thought it was amazing, especially in the yellow flower- however our red flower did not change at all. I introduced the concept of acting like a scientist and the steps of a science lab. We made a hypothesis, or prediction, on what would happen to the flowers.

Making a Forest:

After discussing what forest is and the animals that live there, we made our own forest. On day 1 we traced our hands and arms to make the tree trunk and branches. Make sure to spread fingers out as much as possible to really make it look like a tree. The next day we added leaves.

Clovers:
To celebrate St. Patrick's Day we made clover prints. Take 3 wine corks and glue together (I recommend hot glue). Use it like a stamp and just add stems with a paint brush!