Happy Science Notebook: August 2011

Wednesday, August 31, 2011

Engineering Ground Zero (NOVA)

Building Green
The new season of NOVA kicks off with Engineering Ground Zero. This month, SPARK explores green energy as it relates to sustainable building. From defining alternative energy to understanding the influence of Mother Nature in building construction, these resources shed light on the direction and future of building innovation.
Join us on Facebook and Twitter, or visit the NOVA Teachers and Teachers' Domain websites to tap a wealth of great STEM-related video clips, animations, interactives, and activities.

Keep investigating!
Rachel Connolly, Director of Education, NOVA

Designing Future Cities: Alternative Energy
Can you design the green city of the future?
Take on the role of city planner and work out design solutions that incorporate innovative energy alternatives.
Video (2m 11s), Grades 3-8

Physics of Stone Arches
How do arches stay standing?
Try your hand at constructing a cathedral arch and learn more about the physics behind the arch.
Interactive, Grades 7-12

Green Technology: Sustaining the Earth
How can technology move us toward a greener future?
Explore areas of research and innovation in green technology: renewable energy and conservation; green building; transportation; manufacturing; and pollution and waste management.
Interactive, Grades 6-12

The Structure of MetalWhat makes metal special?
Explore metal at the atomic level and find out what makes it such a versatile material.
Interactive, Grades 6-12

Nature's Super Materials
How is Mother Nature inspiring the next generation of strong materials?
See some of the amazing structures and properties that animals and plants have evolved, and learn about new human-made super-materials they are giving rise to.
Interactive, Grades 6-12

It's Elemental (with example worksheet)

Whether they are created by nature or in the lab, chemical substances are all made of some combination of just 118 pure elements.

These elements come together to produce an amazing diversity of materials. In this interactive, discover which elements are most abundant in the universe, the sun, and the Earth as well as in the human body and in that flashiest of human creations—fireworks.

Also, learn which elements have the most extreme properties on the periodic table.

Launch Interactive

Download

In this interactive periodic table, explore the elements and their properties and abundances.

A previous version of this feature originally appeared on the site for the NOVA program Kaboom!.

EXAMPLE WORKSHEET (with answers)

Elements of the SUN

Pablo Cortez IHM

8-31-11 Wednesday

1st most abundant element of the SUN: Hydrogen
Symbol: H
Family: Alkali metals

2nd most abundant element of the SUN: Helium
Symbol: He
Family: Noble gasses

3rd most abundant element of the SUN: Oxygen
Symbol: O
Family: Nonmetals

4th most abundant element of the SUN: Carbon
Symbol: C
Family: Nonmetals

5th most abundant element of the SUN: Nitrogen
Symbol: N
Family: Nonmetals

6th most abundant element of the SUN: Neon
Symbol: Ne
Family: Noble gasses

7th most abundant element of the SUN: Iron
Symbol: Fe
Family: Transition metals

8th most abundant element of the SUN: Silicon
Symbol: Si
Family: Nonmetals

9th most abundant element of the SUN: Magnesium
Symbol: Mg
Family: Alkaline earth metals

10th most abundant element of the SUN: Sulfer
Symbol: S
Family: Nonmetals

Sources:

NOVA: http://www.pbs.org/wgbh/nova/physics/periodic-table.html

Data provided by PeriodicTable.com. Melting point, boiling point, and density data apply to elements at standard atmospheric pressure.

Magic Rollback Can - Transfer of Energy

Potential and kinetic energy at work in this magical demonstration! Video first followed by a description. Source Link

In our long line of "magical" science, we introduce the Magic Rollback Can. The Magic Rollback Can appears to be a normal can of coffee or oats, but after you roll it along the ground a little ways and watch it come back, you'll be wondering just how it works.

Materials

Coffee or oats can
Nail or other hard pointed object
9-volt battery or object with similar weight
Rubber band
2 paperclips
Tape

Using the nail, make a hole in the middle of the bottom of your coffee or oats can. Be extra careful when using sharp objects. Also, if you are using a coffee can, be careful around the sharp metal edges that you may create when making the hole.
Poke the same kind of hole in the lid of the can.
Tape the 9-volt battery to the middle of the rubber band. Make sure both sides of the rubber band are taped to the bottom of the battery.
Push one end of your rubber band loop through the hole in the bottom of the can and secure it there by attaching one of the paperclips. Once you have it secured, tape the paperclip down.
Stretch the rubber band across the length of the can and push the other end of the rubber band loop through the hole in the lid.
Secure the rubber band with a paperclip and tape it down.
Put the lid on the can. Does the battery rub against the side of the can? If not, you're good to go. If it does, try a shorter rubber band.
Getting the set-up just right may take a bit of experimentation, but you'll get it!
Set the can on its side on a hard surface or short carpet floor and give it a roll. Once the can comes to a stop, try to contain your excitement as it begins to roll back to you!

How does it work?

The Magic Rollback Can is a great example of transfer of energy. When you roll the can, it has kinetic energy. As it slows down, the energy is transferred into potential energy within the twisted rubber band inside the can. The twisted rubber band's potential energy is then transferred back to the can in kinetic energy as it untwists.

The secret to all this energy transfer comes from the weight that you've taped to the rubber band inside the can. While the weight is being pulled down by gravity, it is also being subjected to a twisting force from the rubber band. So long as the force being exerted by gravity on the weight is greater than the twisting rubber band's force on the weight (meaning the weight never goes over the rubber band), the rubber band will continue to twist.

Once all of the kinetic energy from the rolling can has been exhausted by converting to heat (friction) or potential energy (twisted rubber band), the can stops rolling and the weighted rubber band is able to unwind. Because of the weight in the middle of the rubber band, only the ends of the loop are able to unwind and, therefore, the can begins to roll backwards.

Additional Info

If you are looking to take the Magic Rollback Can to the next level, try painting it a solid color. If you do this, observers won't be able to see the apparatus on the ends of the can. This makes the Magic Rollback Can a perfect "Black Box" tool for teachers. Show your students what the Magic Rollback Can does, and have them observe and hypothesize how the can might work.

Physics of the Stone Arches (NOVA interactive)

Arches

Medieval architects were masters at building with stone. But as cathedral design evolved, some medieval architects began to push beyond the boundaries of known structural design and into unknown territory.

With the pursuit of taller and taller cathedrals, any errors could lead to catastrophic collapses. In this interactive, try your hand (safely) at constructing a cathedral arch and learn more about the physics behind the arch.

Launch Interactive

See if you can build a cathedral arch without it collapsing, and learn more about the forces at work.

Editor's Note: The arch diagrams and thrust lines are simplified for illustrative purposes. Our interactive arch exists in a virtual world that does not completely reflect real-world physics.

Wednesday, August 10, 2011

Berry pH Paper

A homemade litmus test to detect acids and bases

No longer must you search for specialty litmus paper. Here is a formula that will allow you to create your own acid and base detecting litmus paper using little more than a bit of fruit.

Materials

1/2 cup of blackberries
1/4 cup of water
2 tablespoons of dish soap
1/4 cup of vinegar
Bowls or other containers
Water
Scissors
White construction paper
Paper towels
Zipper lock bag

Making the Paper

Remove any stems or leaves from your berries and place the berries in a zipper lock bag.
Zip up the bag and mash and mush your berries until they look like jam.
Add a small amount of water to thin the juice a bit.
Mix it all up and pour your berry liquid into a bowl.
Cut some thin strips of the white construction paper and dip them into your mashed berries. Push the strips all the way into the berry mush to make sure they are good and coated with the juice.
After taking your "berry" well-soaked paper out of the juice, pull the strips between your thumb and index finger to remove any excess juice and pulp.
Lay the strips onto paper towels and allow them to dry.
Once your paper strips have dried, carefully pick off any large pieces of pulp or berry skins. You're ready to use your Berry pH Paper.

Putting Your "Berry" Own pH Paper to the Test

Pour 1/4 cup of water into a bowl and mix in two tablespoons of dish soap.
In a separate bowl, pour 1/4 cup of vinegar.
Dip half of one strip of your Berry pH Paper into the bowl containing dish soap and water. Do the same thing with another strip of Berry pH Paper, but this time dip it into the vinegar.
Set the Berry pH Paper strips onto a piece of paper towel to dry. This should only take about five minutes. Make sure you label the pH strips to remember which strip was dipped in which liquid.
What color changes did you notice? Which liquid was an acid? Which liquid was a base?

Cool... but how do I use it?
Blackberry pH Paper turns pinkish red in acids and turns deep purple in bases.

How does it work?

Blackberries, blueberries, strawberries, and a bunch of other flowers, leaves, and stems are naturally occurring pH indicators. This is true because they contain chemicals from the anthocyanin family of compounds. Anthocyanin compounds turn red in acids and blue in bases when they are in their pure form. In this case, we have the anthocyanin compounds within the juice of the berries. This results in a less distinct, but still distinguishable, color change.

Additional Info

Try testing out other liquids like milk, soda, or fruit drinks to find out which ones are acidic and which ones are basic.

Tuesday, August 9, 2011

Science Experiment Links

Experiment Categories

Earth Day Experiments:

Clean Air - Denver's Brown Cloud
The Amazing Oil Clean-up Polymer
Vanishing Styrofoam
Gardening with Water Jelly Crystals
The Power of Compact Fluorescent Lights

Top Ten Science Fair Project Ideas SOURCE Experiments

SOURCES:
Experiment Library