Monday, January 23, 2017

Polymer Challenge

Students learn about polymers and use the scientific method to test variables to make the bounciest Silly Putty Slime.

Engage

Do disappearing water in cup with polymer trick


talk about polymers and how sodium ions in diaper crystals attract water into the polymer

Explore

Make instant snow


  1. extract sodium polyacrylate from two diapers
  2. put in cup
  3. add cup of water
  4. stir to make instant snow

Demonstrate making Silly Putty Slime

Glue:BoraxINWater ratio of 1:1
demonstrate liquid properties by allowing to settle into a container
demonstrate solid properties by pulling and breaking slime

Elaborate

Challenge to Make Bouncier Silly Putty Slime (https://www.teachengineering.org/sprinkles/view/cub_creepysillyputty)

Provide
Each group needs:
  • 4 plastic spoons
  • 1 bottle of saturated Borax® solution
  • 1 bottle/tube food coloring (any color)
  • 1 bottle of water
  • 1 bottle of 2:1 Elmer's® glue/water solution
  • 4 plastic cups
  • paper towels
For the class to share:
  • 1 box of small plastic zipper bags

Procedure

Making Silly Putty - Instructions from https://www.teachengineering.org/sprinkles/view/cub_creepysillyputty
Instructor note: students make small batches of different mixtures to create a variety of putties. Do not hand out supplies until steps 4 and 5, listed below.
  1. Show students the four ingredients they will be using for their putty: food coloring, water, Borax solution and glue solution. Tell them they only get one bottle of each ingredient, so they should use it wisely.
  2. Tell students that each batch of putty they make should consist of exactly four spoons of liquid, the ingredients of which are distributed any way they choose. For example, they could try one spoon of glue, one spoon of Borax, and two spoons of water. Tell students they should use two drops of food coloring per batch.
  3. Tell students that their goal is to make putty that is very elastic, but not super sticky. (Note: to describe "too sticky," tell students their putty should easily peel from the sides of the cup or even their hands. It should have a consistency similar to cookie dough that easily comes off of waxed paper, not peanut butter that must be scraped off.)
  4. Pass out paper to each group. Instruct them to draw a line down the center of their papers and label the left side: Trials, and the right side, Results.
  5. Inform students that the best way to mix the putty is as follows:
  • Decide on a recipe to try consisting of four spoonfuls of available ingredients.
  • Write down the recipe (the ingredient and the number of spoonfuls) they will be mixing on a blank piece of paper. Have students call their first recipe Trial 1 (followed by Trial 2, Trial 3, etc.)
  • Put the two drops of food coloring and pre-selected amount of glue mixture that they determined they will use for each recipe/test into a plastic cup and mix well.
  • Next, add water and mix well.
  • Add the Borax mixture and mix until a solid forms.
  • Scrape the solid off the spoon and put it back into the cup and mix thoroughly again three times. If liquid remains in the bottom of the cup after three mixes, take out the solid part and have them mix it with their hands until it is no longer wet.
  1. Have students describe the silly putty consistency on their papers (under Results). Specifically, report on each batch's texture: too elastic, perfect, too sticky, etc.
  2. Repeat steps with a new recipe. Wipe off and reuse the spoons, but get a new cup for each different recipe. They have a maximum of four recipe trials.
  3. Have students try several recipes, again trying to create a putty that is elastic but not sticky.
  4. Have students show their most elastic putty to the class, and have them describe their recipes.
  5. If desired, offer zipper bags to students who wish to save their putty to take home. Remind them to "zip" their bags because the putty dries out quickly.

Evaluate

bounce putties and see which bounces highest.
ask where else polymers could be useful - self-watering plant soil, erosion control

Wednesday, January 18, 2017

Blood Typing Lab

Use Innovating Science ABO/Rh Blood Typing Kit (available from Amazon.com) or make your own artificial blood as described in http://www.scienceinschool.org/content/investigating-blood-types
 

Sunday, January 15, 2017

Chemistry Science Club Ideas

Links to specific resources coming soon...

Scientific Method:


  1. Observation
  2. Research
  3. Hypothesis
  4. Experiment
  5. Analysis
  6. Conclusion
  7. Write-up

Importance of Measurement

  • Repeat measurements, find average, discuss differences
  • metric S.I. units

Chemistry Skills and Concepts:

What is Matter?

  • Atom, Molecule, Compound, Mixtures

Phases and Phase Changes.

  • Solids, Liquids, Gases 
  • Melting, Evaporating, Condensing, Freezing, Sublimating, Deposition (make icecream)
  • non-Newtonian liquids

Ions and Salts

  • test solutions for salts and identify anions and cations

Acid-base
Separation
  • chromatography (t-shirt/sharpie, coffee filter/marker)
  • density column
  • based on electric charge (salt and pepper, hydrolysis )
Other
  • elephant toothpaste (H2O2 with yeast)
  • polymers (make slime, bouncy balls,  )
  • kitchen science (make gummies, rock candy, fizzing sherbert, extract iron from cereal)
  • buoyancy (predict if x will float)

Friday, January 6, 2017

DNA Extraction

Goals: 

Review what DNA is
Extract DNA from strawberries, bananas, blueberries, cheek cells
Compare DNAs

Background:

Technique: 

Use method described in:  Science Buddies Staff. "Do-It-Yourself DNA" Science Buddies. Science Buddies, 5 Aug. 2014. Web. 6 Jan. 2017

Materials and Equipment 

  • Measuring cup
  • Measuring spoons
  • Isopropyl rubbing alcohol, 70% (1/2 cup)
  • Salt (1/2 tsp.)
  • Water
  • Dishwashing liquid (1 tbsp.); Liquid detergent you use for hand washing dishes (e.g., Dawn®)
  • Glass or small bowl
  • Cheesecloth
  • Funnel
  • Tall drinking glass
  • Strawberries (3), bananas, blueberries,...
  • Re-sealable plastic sandwich bag
  • Test tube or small glass jar, e.g., spice jar or baby food jar
  • Bamboo skewer or other thin rod. They are available at grocery stores. Alternatively, you can use a toothpick if your test tube or small glass jar is no taller than a toothpick.
  • Lab notebook

Results: 

Compare DNAs in tubes
Use stirrer to put DNAs on labelled microscope slides - observe

Summary:

Review DNA structure, translation to protein, results of DNA comparison
Review technique fails and successes for next time
Hand out DNA extraction method printout

Wednesday, December 28, 2016

Electricity


Engage

Lead with video of Bill Nye asking questions about electricity or ask what is electricity

Explore

Provide wires, battery, lamp, switch and challenge students to make the bulb glow
Discuss what worked and what didn't

Explain

Introduce idea of closed circuit, energy source (battery), electrons

Atoms

  • basic building blocks of life and matter.
  • exist in over a hundred different forms as chemical elements like hydrogen, carbon, oxygen, and copper. 
  • are tiny - a copper penny (if it actually were made of 100% copper) would have 32,000,000,000,000,000,000,000 atoms of copper inside it.
  • are made of protons, neutrons, and electrons with a center and surrounding the nucleus are a group of orbiting electrons.

Rutherford atom model


  • electron can escape orbit of the atom and become free. Free electrons allow us to move charge, which is what electricity is all about.
  • Elements with very mobile electrons, are called conductors. These are the types of materials we want to use to make wires and other components which aid in electron flow. Metals like copper, silver, and gold are usually our top choices for good conductors.
  • Elements with low conductivity are called insulators. Insulators serve a very important purpose: they prevent the flow of electrons. Popular insulators include glass, rubber, plastic, and air.
 https://learn.sparkfun.com/tutorials/what-is-electricity

Model a Circuit


  • have students line up in circle - hand each a potato
  • label one person a battery, one a light
  • ask them to pass the potatos around pretending they are electrons, lighting up the light
Explain that a circuit is a closed, never-ending loop of conductive material. conductive wire? components? NO insulating gaps. Electrons are not generated, just passed around.

Elaborate 

Make a flashlight to take home

http://www.energizer.com/science-center/how-to-make-a-flashlight

Need:
  • 2 D cell batteries 
  • Number 22 insulated copper bell wire 
  • Cardboard tube (paper towel) cut to 5.125" in length 
  • 3-volt flashlight bulb 
  • 2 brass fasteners (brads) 
  • Small cardboard piece for holding bulb 
  • Paper clip 
  • Electrical Tape 
  • Bathroom-size paper cup

Demonstration: Make and Compare batteries

Potato Battery http://www.wikihow.com/Create-a-Potato-Battery vs.
Lemon Battery http://www.wikihow.com/Create-a-Battery-from-a-Lemon vs.
Range of household batteries

Need:
  • batteries AA, AAA, C, D
  • potatoes
  • lemons
  • LED light bulb
  • galvanized nails
  • pennies
  • alligator clips
  • voltmeter

Evaluate

Ask what would happen if light-bulb burns out?

Sunday, December 18, 2016

Best Science Club Resources

I have been all over the internet looking for great ideas for Science Club topics. My requirements are that I can do experiments with the kids within 60 minutes, that there are several active components, and that we see something unusual: my children seem to have a high "awe" threshold.

These are my go-to websites:

http://pbskids.org/zoom/activities/sci/

This PBS Kids website has dozens of activities in topics of Chemistry, Engineering, The Five Senses, Forces, Life Science, Patterns, Sound, Structures, and Water. Activities take from 5 to 30 minutes . There are labelled activities that help the environment


https://www.exploratorium.edu/snacks

"An Exploratorium Snack is a hands-on science activity. Science Snacks are tabletop exhibits or explorations of natural phenomena that teachers or students can make using common, inexpensive, readily available materials.
Science Snacks are divided into easy-to-follow sections that include instructions, advice, and helpful hints. Each one begins with a photo and/or video, a short introduction, and a list of materials. Other sections include assembly instructions, how to use the activity, and explain what’s going on, science-wise. Most Science Snacks can be built by one person; we indicate if a partner or adult help is needed, this is indicated. A section called "Going Further" offers interesting bits of additional scientific and historic information."


http://www.science-sparks.com/

Very nice website and blog with lots and lots of activities for younger pre-school to lower elementary school children.  More for one-on-one activities, but many can be scaled to small groups.
"Here at Science Sparks we are passionate about making science fun for kids. All our activities are easy to do and use only equipment and materials commonly found around the home. Science for kids doesn’t have to be complicated and boring, it can be great fun for both children and adults.
Science based activities offer endless creative learning opportunities and are a great way to spend time with your children. We’ve had some of our best chats while drawing on filter paper and making patterns in milk.
Science activities can also be fantastic for inspiring reluctant readers or children who like to be very hands on with their learning. Children are naturally curious and science activities are a great way to help them explore the world around them. Learning how to think logically and follow a scientific process has huge benefits to children as they grow up, helping them to plan, communicate, work creatively, solve problems and much more."


http://www.nasa.gov/audience/foreducators/k-4/index.html

"Search hundreds of resources by subject, grade level, type and keyword. These lesson plans and teaching materials support your STEM curriculum.
NASA Wavelength A digital collection of Earth and space science resources for educators of all levels – from elementary to college, to out-of-school programs.
NASA Education YouTube Channel"



https://www.teachengineering.org/

"The TeachEngineering digital library is a collaborative project between faculty, students and teachers associated with five founding partner universities, with National Science Foundation funding. The collection continues to grow and evolve with new additions submitted from more than 50 additional contributor organizations, a cadre of volunteer teacher and engineer reviewers, and feedback from teachers who use the curricula in their classrooms.
TeachEngineering is a searchable, web-based digital library collection populated with standards-based engineering curricula for use by K-12 teachers and engineering faculty to make applied science and math come alive through engineering design in K-12 settings. The TeachEngineering collection provides educators with *free* access to a growing curricular resource of activities, lessons, units and living labs."



http://www.stemclubs.net/activity-categories/

  • One-off activities are completed in one session. They are often highly engaging and can have a real wow factor.
  • Short projects are any activity that takes club members two to three sessions to complete. Many of the shorter projects will include demonstrations or experiments that can be used as one-off activities.
  • Long projects are activities that take half a term or more to complete and might be considered a long project. Completing a long project can be very rewarding, especially if there is an award or a prize involved.

Each activity is categorized as Science, Technology and Engineering, Maths, or Cross Curricular.

Wednesday, December 14, 2016

Sound

From Teaching Physics with Toys, from 101 Great Science Experiments, and from https://www.teachengineering.org/lessons/view/cub_energy2_lesson05

Learning Objectives


After this lesson, students should be able to:
  • Give several examples of engineering products that involve sound.
  • Describe sound as a form of energy.
  • Define volume, pitch and frequency as they relate to sound energy.
  • Describe sound energy as traveling in waves.
  • Explain sound as a form of communication.

What is sound?

Engineering Connection

Engineers use their knowledge of sound waves to create radio and sonar devices. Sound waves traveling through the air are collected by radio antennas. Sonar devices send ultrasound waves into an ocean and create images based on which waves are bounced back to the device. Ships use sonar to navigate and map the seabed by measuring water depth. Sonar is also used to search for undersea objects such as wrecks, submarines, rocks, icebergs, whales and fish. Engineers also design instruments that "listen" to ultrasound and infrasonic sound waves. Ultrasound can detect tiny flaws in materials used to make parts — from bridge bolts to aircraft wings.


Experiment: Sounds Produced with Different Lengths of Ruler 

  1. Place a 12 inch ruler flat on a table. Let 4 inches of the ruler extend over the edge of the table 
  2. Hold the ruler securely to the table with one hand and pluck the other end of the ruler that sticks out over the end of the table with the other hand
  3. have students duplicate  steps 1 and 2 with their own rulers
  4. ask students "What did you see?" Vibration. "What did you hear?" Sound
  5. have students experiment with different lengths of ruler extending over the end of the table. Point out that they are making different sounds.
Need: rulers

Experiment: Sounds Produced with Different Rubber Bands

  1. Make a box guitar. Pluck rubber bands one at a time to make different sounds
  2. ask students "Why are the sounds of the various bands different?" The rubber bands have different masses and are under different amount of tension. These differences contribute to different frequencies of vibration and therefore different sounds
  3. Explain that the energy from a vibrating object transfers to gas particles, which pass their energy to adjacent particles, producing a wave.
Need: tins
rubber bands

Experiment: See sound by building a sound gun

Need:
thin plastic table cloth
tube
stiff paper
thin strip paper
pencil
rubber band
tape

See Sound






Introduction/Motivation - Volume, Pitch, Frequency

Have the students close their eyes and sit quietly for 30 seconds. What did you hear? (Have a few students describe the different sounds they heard.) These are all sounds and we will be learning about sound energy today.
Now tap on your desk. How would you describe that sound? Can you tap on your desk louder? Now, really softly? What do we call this change in sound? We call this characteristic of sound, volume.

Now, tap on your desk using a pencil. What is this sound like? Is it a higher sound? We call this characteristic of sound, pitch. You have just learned two of the three important characteristics of sound energy that we will discus today — sound volume and pitch.

To travel, sound energy must vibrate molecules. These molecules move in a sound wave. Sound frequency is how much a sound wave is vibrating. Frequency is the third characteristic of sound that we will discus today. Let's see what this looks like!
Classroom demonstration: Use a large spring or slinky to demonstrate the characteristic of frequency. Expand the slinky and have students hold each end. Make sure the students stand very still and do not shake the slinky.
  • To describe longitudinal waves, grab a few coils of the spring and let go of them. As the students watch the waves travel through the spring, explain that these waves are longitudinal waves. Explain that the release of the coils represents the source of the sound vibration and that this sound is moving longitudinally across the slinky. Harmonic sound waves are usually longitudinal waves.
  • To show transverse waves, strike the spring at right angles to its length. Have the students describe the up and down motion of the spring. Explain that this motion represents transverse waves. Radio waves are examples of transverse waves used by engineers to send messages over long distances. Transverse waves also travel on the strings of instruments, such as guitars and banjos.
  • If possible, show Professor Dan Russell's excellent online animation of longitudinal and transverse waves at http://www.acs.psu.edu/drussell/Demos/waves/wavemotion.html.

Other Frequencies

Our ears pick up a wide range of frequencies. However, some animals hear frequencies that are too high-pitched for our ears to detect. These frequencies are called ultrasounds. Other creatures detect frequencies known as infrasonic sounds that are too low for our ears to detect.
To detect what our ears cannot hear, engineers design instruments that are able to "listen" to ultrasound and infrasonic sounds. Ultrasound can detect tiny flaws in metals, plastics and other materials used to make parts — from bridge bolts to airplane wings. Ultrasound used in medical sensing equipment helps us "see" the development of a baby inside its mother's womb. Ships use sonar, a type of ultrasound, to search for undersea objects such as wrecks, submarines, rocks, icebergs, whales and shoals of fish. Sonar can also measure the water depth so it is useful for ocean navigation and mapping the seabed.
Some electronic equipment built by engineers turns ultrasound or infrasonic sound signals into electrical signals, and further into sounds of lower pitch, which we can hear as "pings," or into visual patterns of lines and colors that we can see on monitor screens.

Experiment: Traveling Sound

Traveling Sound - Students explore how sound waves move through solids, liquids and gases in a series of simple sound energy experiments. They see how engineers use their understanding of the properties of sound energy when designing recording studios, libraries and concert halls.

Every sound, whether it is from a rubber band twanging or a loud speaker cone, is created by vibration. You cannot hear sound in a vacuum because sound reaches your ear as vibration, and there must be something to vibrate. Usually, the medium that vibrates is air. When the sound source vibrates back and forth, it pushes the air around it back and forth. The sound travels through the air as it is pushed back and forth in a chain reaction that is being alternately stretched and squeezed. This moving stretch and squeeze is called a sound wave.


  • Can sound energy travel through solids? Students place their ears on a desk or table as they tap or scratch on the top. They compare that to the same sound made when their ear is not pressed to the table.
  • Can sound energy traveling through liquids? Fill a large bowl or bucket (metal works best) with water. One student taps two spoons together under the water. Two other students observe and compare the tapping sound they hear, as heard through the air and as heard by placing an ear against the bowl.
  • Can sound energy traveling through gases (air)? The students feel their throats gently during each of these tasks:
- Hum with your mouth and nose open.
- Hum with your mouth open and nose closed.
- Hum with your mouth closed and nose open.
- Hum with your mouth and nose closed.

Lesson Closure

What is sound energy? (Answer: It is the energy produced when sound is created.) What are three characteristics of sound energy? (Answer: Volume, pitch and frequency.) We may not be able to hear every sound that exists, but engineers use all types of sounds to create devices that help people. Engineers have designed instruments that can "hear" ultrasonic and infrasonic sound that humans cannot hear with their ears. Sound is a type of energy that we use every day, especially when our families, friends and our teachers talk to us.