Searching the stream

Now that the weather is good, there is only one thing my youngest, Gwen, wants to do: Play at footbridge Park. What's not to love? Huge old trees to climb, a fun playground and the Paulinskill to explore!

Which is why she was so excited to search for macroinvertebrates as part of our recent Trout in the Classroom activity. Messy, wet fun with interesting, tiny creatures living on the banks of the stream? Sign her up!

Macroinvertabrates have no backbones, but are large enough to see with the naked eye. In a stream ecosystem many are immature insects or larvae. They serve as important food sources for larger organisms, and as a bioindicators to scientists studying the health of a stream.

Investigating macroinvertebrates shows children the amazing biodiversity lurking just under the rocks in a river, helps them understand the connections between species in an ecosystem, and is just plain fun. It also gives children the opportunity to practice their skills of observation and categorization. These are fundamental skills for the study of biology, and science in general.

First thing you'll need is a kit, like the one below.

 Here's what it includes:

• A plastic bin -- Great for larger organisms like crayfish or minnows, as well as acting as a carry all.
• Towels -- You know you're going to get wet, right? Plan ahead.
• Trowels and spoons -- Perfect for digging and sifting through soil in the riverbed.
• A fish net -- Because it's fun to catch small fish and similar creatures. Quick little buggers! Also good for sifting through debris.
• A foam egg carton or ice cube tray, white -- Perfect to separating and temporarily storing invertebrates while you categorize them.
• A ruler -- Helpful when trying to use a field guide to identify an organism.
• Magnifiers -- Get up close and personal.
• Pippettes/Eyedroppers -- to place water into your tray or collect algae samples.
• A flashlight -- Light can be dim under trees on some riverbanks. Bring your own light.
• A guide -- I like dichotomous keys, like this free one. These types of guides are really easy for kids to use. They're like "choose your own adventure" novels, but for science! (Make sure you put your guide in a sealed plastic bag to keep it safe in wet conditions.)

Beyond that, you just need to get out there and explore! Keep a journal. Take pictures. Get wet and muddy. Get to know what lives in the stream or pond near you. You'll be amazed at all the little creatures you never noticed before!

Once you have a good sense of what's there, you can use that information to evaluate how healthy your stream is. The number, diversity and types of creatures living there all hold clues. Many areas have citizen science programs where volunteers can help catalog macroinvertebrates, providing important information for ecologists and scientists. 

And please, be sure to put the amazing creatures back where they belong when you are done. They deserve gentle treatment and respect.

Happy hunting!

Teaching Genetics: Characteristics and Traits

Students are always fascinated by their heredity, but what they take from their previous generations and express today in the way they look. Naturally curious, every child I've ever met has inventoried the many ways they look like -- or unlike -- their relatives. It's part of a human's natural development to figure out his or her place in the world, and kids often use their powerful skills of observation to do this.

So teaching genetics and heredity makes sense. Sometimes an understanding of the topic comes more easily to a child than it does to adults, simply because they are paying attention more than we typically do.

Often, when people start to consider phenotype (i.e. the outward expression of our genetic traits), they look first to the obvious -- eye color, hair color, skin color, inherited disease, etc. But I think it's fun to look at somewhat odd traits that we may not even realize are genetic! It puts in perspective the amazing amount of information encoded on our DNA!

For this I really like the free activities from The University of Utah as part of their Teach.Genetics resources for teachers. Start with the Inherited Human Traits: A Quick Reference Guide. Here you'll learn that things like left and right handedness, the ability to roll your tongue, the ways you ears attach to your head and the way to fold your hands are all genetically linked. Students get such a kick looking for these traits in themselves and classmates.

The website provides a survey activity, where you can tally the results and create a bar graph based on the results. (Always fun! Literally, one of my students today shouted, "A survey? I love survives ") Or you can continue the research -- asking friends and family about the traits -- and either graph the data or create a fun family tree based on it. (The family tree is easily adapted to homeschool use, and my daughter and I plan to complete this activity at home.) I also love playing Traits Bingo using the research.

There is also Generations of Traits which is a really fun hands-on activity the shows the passing of genetic trait from grandparents down. I like it because ti makes it clear that though may share traits with others in your family, the actual genes always come from your parents. It also shows how completely random your genetic mix is. This would be a fun one to extend with a study of the probability involved with each generation.

Fun with dry ice

Let's face it, dry ice is fun. A super cold solid form of carbon dioxide, dry ice sublimates at room temperature, creating an eerie fog. Not only is dry ice great for science experiments, it's fun for parties too.

Luckily it's not that hard to get either. I have a local distributor called The Ice Factory, where I can drive right up and ask for a 30 lb. block any day of the week. You need to bring a cooler with you, or your frozen treasure won't last very long. A good pair of work gloves are needed to allow you to handle the stuff. I often ask to have it pelleted, for ease of use. But, as you'll see below, a big block of dry ice can be a lot of fun too.

So what do you do with your dry ice, once you've got it at home? I like to let kids explore the pellets alone first, observing the fog and talking about what's happening. Then we add warm water. The warmer the water, the more fog you get, because the difference in temperature affects the rate of sublimation. If you use a large clear container, kids can also see the bubbling as gas is generated. A little food coloring helps.

Then I like to add some dish soap. Suddenly everything changes, and big cloudy bubbles emerge from the container. Popping them releases the fog held inside. It's a ton of fun. Again add a bit of food coloring for added excitement.

Later, when all the dry ice is gone, the frothy, frozen soap will be left behind. It's lots of fun to play with too!

Remember how I said I like to get a big block of dry ice as well? If you use a power drill to add a wide hole to the top of the block and smaller ones to the sides, you can create a really amazing demonstration. You'll need magnesium ribbon as well.

Magnesium is a common alkaline earth metal. It's highly reactive and burns readily, producing a bright white light. Which is pretty cool all by itself, right?

When you place the magnesium ribbon in the dry ice and light it, things get dramatic. The burning magnesium can seal oxygen from the carbon dioxide in the dry ice, burning brightly without the need for other oxygen. In turn, the exothermic reaction speeds the sublimation of the dry ice, resulting in even more fog. The science is fun, but the visual is even better!

If you decide to try this at home, be sure to do it outdoors, or in a well ventilated area. And be sure to remove flammable items. This can get hot and bits of magnesium can be thrown off.

5 Things Your Young Business Person Needs to Know

The next session of TREP$, the exciting entrepreneurship program for 4th through 8th graders, is about to begin. The initiative is designed to serve as an inspiration for young people to think creatively and to put their ideas into action by creating a new business.

Over the last two sessions, we've all learned a lot about being a young entrepreneur. Here are some tips, from my own young businessperson, Caitie, who is co-creater of Spa Girls, a business that been successful at two TREP$ Marketplace events with their all-natural bath salts, lip balms and body sprays.

1. Don't underestimate yourself. Never assume you aren't making something worthwhile. Try to make the very best product you can, so that you can wow your customers. Make a little more product than you think may sell, and trust that you will find a way to make the sale if you are creative and persistent.
2. Don't undervalue your time. Making quality products or providing good services takes time and hard work. Remember that your time is valuable and important. Consider it when you set your prices.
3. Don't reinvent the wheel. Make something new and special. Make something that is unique. Or put your special spin on something that exists. Whatever you do, make it yours. That makes it something the customer will want.
4. Always wear a smile. Be professional. Wear your best clothes and don't eat stinky foods. You want to present yourself well to your customers. Customer service is very important. 
5. Pricing is important. Charging too much or too little can mean you lose sales. Aim for the middle. See what other companies change for similar products or services. Be very aware of how much money you've invested, and plan to make back your expenses by the time you sell half your inventory.

Gwen, my 7 year old, also wanted to throw in a tip as well. She says, "Little sisters and brothers make great assistants!"

Hot and cold reactions

As part of our recent Chemical Reactions Workshop, we explored endo- and exothermic reactions. Many chemical reactions create light, heat or other forms of energy. An exothermic reaction is one in which heat is made and released by the reaction. The term is obvious if you look at the roots: ex = out/outside, therm = heat. Therefore, endothermic (en = in/inside) is a reaction where energy (in the form of heat) must be pulled in for the reaction to occur.

Both are fun and easy to demonstrate. Grab the following supplies:

• 2 Styrofoam cups (reusuable insulted cups are even better)
• 1 thermometer
• baking soda
• citric acid (you can find it with the canning supplies in the grocery store)
• hydrogen peroxide
• a packet of yeast

For the first reaction, create a baking soda solution by adding baking soda to warm water one teaspoon at a time, stirring after each addition. Stop when no more will dissolve. Let the solution cool to room temperature, then place it in your cup. Use the thermometer to check the temperature. Add a teaspoon of citric acid. The solution will fizz and the temperature will drop. Keep adding citric acid and see how low you can make the temperature go. This is an endothermic reaction. Kids can put their fingers into the solution to feel the cold directly. Just wash your hands afterwards.

For the second reaction, we're going to generate heat through a decomposition reaction. Fill your cup with hydrogen peroxide. Check the temperature. Slowly add the yeast, a little at a time. Soon you'll have a big bubbling mess and spike in the solution temperature. Keep feeding the reaction. How high will the temperature go? Again, kids can touch the solution without fear. 

Older student may enjoy exploring the concepts of enthalpy and entropy as well. Have fun playing! Let me know what you discover!

Metal reactivity awesomeness

So, one of the things you talk about in introductory chemistry is the activity level or reactivity of different materials. Because reactivity tends to mean fizz, flash and boom, the visuals often make for great demos. Specifically, the activity series of metals can be instructive, as you can use it to predict how different metals may react in similar reactions.

This experiment is an oversimplification, I know, but it gets idea across for younger students.

Here I react three metals -- aluminum, zinc and copper -- with the commonly available muriatic acid (hydrochloric acid). It's a cheap and easy way to visualize the reactivity of different metals, using easy to find materials. Plus, it's fun. To extend this, you can try different metals, for example an iron nail. See what you have in your home or lab. Then look at an activity series chart and the Periodic Table and draw conclusions.

Safety notes: This reaction produces noxious gas and heat. Goggles and gloves should be worn. Seriously.

Sorry for the video quality. First time with a new camera. Plus I have a sinus infection, so my voice sounds terrible.

Making Matters: 5 things to do with paper towel rolls

We all know that toilet paper and paper towel rolls are one of the all-time classic craft supplies in the typical classroom. Which is awesome -- I love toilet paper owls and other fun projects made from these upcycled marvels. But what about using such humble supplies for science? Here are five projects
to try at home.

Ok. One toilet paper roll owl. I can't help myself.

1. Marble Slides -- Break out the masking tape and get ready to have some fun! Using whole and halved rolls, junior designers can attach tubes to any wall creating multi-layered slides for marbles to zig-zag towards the floor. If you want to get some motion going, try attaching rolls to foam board using brass brads or tacks!
2. Spectroscope -- Find all the colors of the rainbow in white light. Using black construction paper, cut a circle the size of the paper towel roll opening. Cut this circle in half. Tape half of the circle to one end of the roll, being sure to tape well around the edges. Attach the other half circle to the same end, leaving a narrow slit across the center. Again, tape well at the edges. Now,with your eye at the open end, look at a CD held near a light source (an incandescent bulb just behind the bulb is great). The CD will diffract the light, breaking it into a rainbow that you can see through the slit. Wow!
3. Kaleidoscope -- Cut you paper towel tube to 8 inches. Longer will make it tough for enough light to travel to the eye. Use black construction paper to cover one end of the tube. With a pencil, poke a hole in the paper. Use clear tape and apiece of clear cellophane or acetate (a report cover, a transparency, etc.) to create a triangular tube that will fit inside the tube. Slide it in. Cover the other side of the tube with plastic wrap, pushing it down to make a little pouch and securing it with tape or a rubber band. Add beads, sequins, gems or anything small and shiny. Cover with another piece of plastic wrap and secure in place. Now hold it to the light, look through the hole and enjoy the power of reflected light as it creates an amazing display!
4. Telescope -- Using construction paper create a roll that can just fit inside the paper towel roll. Ideally, you'll want two double-convex plastic or glass lenses, one 150 mm and the other 300 mm. If you can't come by those, try magnifying glasses - one larger and weaker and the other smaller and more powerful. You may have to experiment with different options. Tape the smaller lens onto the construction paper tube. Tape the weaker one onto the cardboard tube. Then fit the open end of the construction paper tube into the open end of the cardboard tube. Look through the stronger lens. Move the construction paper tube in and out until the object you're looking at is focused. 
5. Pulley Towers -- Grab some old thread spools, bamboo skewers, cotton string and toilet paper rolls to explore one of the most fun simple machines. Use the rolls to make two towers -- feel free to go big, stacking two of three rolls together. To form the base, cut slits into the bottom of the tower, spread out the "feet," then tape them to a table. Thread the spools onto the skewers and place them between the towers, poking holes into the cardboard as needed. Then it's time to play! Use the string wound in various ways through the pulleys to see how the number and placement of affects the what you can lift.

   

   That is one complicated pulley system!

Whew! That's a lot of fun with paper towel rolls. I'm going to take a bit of break. Come back later this week for 5 MORE fun ideas!