October is…… And, the winner is ……

You could say that October is Science Month!

Next week features the announcements of the Nobel Prizes.  So, look for a number of science related stories and features from various science organizations and businesses.  You can anticipate that the news will be filled with science applications connected to the winners of the Prizes in medicine, chemistry and physics.

Additionally, October generally features announcements for various science competitions.  Check out the Intel, Siemens and other notable companies as they begin to announce their regional and national activities.  (You can also check out Discovery Channel, National Geographic, and Science Channel – for many activities, lesson plans, etc.)  There are sites with monthly themes such as the Siemens Science Day in addition to topic specific sites.

ncw-candy-banner

October features National Chemistry Week (October 19-25, 2014).  This years theme is the Sweet Side of Chemistry – Candy.  There are a number of activities planned around the United States.  These will be hosted by Local Sections of the American Chemical Society, as well as Student Chemistry Clubs.  You can find teacher resources and associated materials at the American Chemical Society NCW website.  Of particular note – related to this NCW topic – was the dedication of the second National Chemical Historic Landmark related to the production of sugar on October 1.  This Landmark recognizes the work of Rachel Holloway Lloyd, a woman chemist.  (The first recognized the work of Norbert Rillieux, whose birth record states “Norbert Rillieux, quadroon libre, natural son of Vincent Rillieux and Constance Vivant. Born March 17, 1806. Baptized in St. Louis Cathedral by Pere Antoine.”  More information about the work and life of Rillieux can be found here.)

October is a great time for slime, glowing science, bubbling punch, and other fun home/class experiments.  Take a few minutes to do a quick search of the American Chemical Society education resources while you are looking at the Sweet Side of Chemistry – to find a bunch of “goolish” fun activities.  (You can also find sites related to Zombies, Bone Chilling Science, Vampires, and even a bit of graveyard science.)

Have fun and don’t forget to stay safe!  (PS if you need safety resources you can always pick up a copy of Staying Safe while Conducting Hands-On Science.)

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Volcanoes – Beyond baking soda and vinegar

Are you working on a volcano lesson plan?  Want to do something more than just the traditional baking soda and vinegar eruption?  How about exploring the properties of liquids?

When studying volcanoes, the topics of molten rock, lava flows, lahars, and pyroclastic flows are typically included.  Depending upon your lesson plan, you might have a brief mention of how different materials “flow” at differing rates, or how different lavas have different flow properties based upon the silica content.  This flow property is called viscosity – i.e. the property of a fluid that resists the forces causing the material to flow.

Everyone has some hands-on knowledge of viscosity.  Think about the difference in the flow of water versus maple syrup or motor oil on a cold morning versus a hot day.  Yet, we typically don’t do any hands-on science related to this physical property of fluids.  An Earth Science – Volcano lesson is a wonderful place to add this hands-on activity.

Now for your recommendations.

From SEED – A laboratory on the Viscosity of Liquids

From the Royal Society of Chemistry – Viscosity

Or, from Sophic Pursuits – Viscosity Explorations

Some safety precautions.  Know the materials you are using.  The Viscosity Exploration uses dish soap, vegetable oil, corn syrup and water.  It also looks at the change in viscosity with temperature.  So children need to work with an adult to make sure there are no burns.  But, the experiment can be done using ice water, cold water and hot tap water.

Just remember to be safe!

Shake, Rattle and Roll – Earthquake Adventures

When an earthquake of a large magnitude hits, you generally see it on the news.  Even small magnitude earthquakes make the news if they happen in areas where earthquakes are not expected by the general public.  They can be frightening, as we have a limited ability to predict an earthquake and it is disconcerting when the ground moves beneath your feet.

But, you can have some fun exploring what happens – “when the earth moves under your feet”.  (In reference to an old rock and roll tune.)

You can make your own “shaker-table” either out of gelatin or simple materials – sand, lids and blocks.  Here are some sites to allow you to make a shaker-table and test some building construction:

From Teach Engineering.com – a Jello, tooth pick and marsh-mellow

From eHow – shaker table

From FEMA – a teachers resource

From Squidoo – Multiple Resources

So have fun creating your own mini-seismic event!

Time to Heat Things Up

The Polar Vortex has been in the news lately and many of you have experienced some very cold temperatures.  But, just as the weather is warming; we can do a bit of hands-on science to look at the properties of heat.  Thus, we can heat things up a bit!

On Jan. 13, 1864, Wilhelm Wien a German Physicist who received the 1911 Nobel Prize in Physics was born. His work on the theoretical nature of heat allowed Max Planck to resolve the problem of radiation in thermal equilibrium and allowed for the development of techniques to measure high temperatures.  This makes it a perfect week to focus on “heating” things up a bit.

Heat can be transferred three ways: conduction, convection and radiation. Here are a few resources to help you explore the heat transfer.

From the University of Wisconsin – Here is an animated activity.

Science Games from Science Kids

From NeoK12 – Heat Transfer Games, Activities and Lessons

And finally from Discovery Education and Siemens Science Day – An Downloadable Experiment.

Have fun exploring how things heat up or cool down as the case may be.

Making Butter is all about Physics

The author of “CookWise” and “BakeWise” writes about the science behind various aspects of cooking and/or baking.  For some food items, its all about the physics.  For biscuits, it is about the steam generation.  For butter, it is all about the agitation and breaking of the suspension.

I have recently started looking into the physics of making butter – and while there are great hands-on science activities that relate to making butter – there is not really a good explanation of what is happening on a microscopic level.  (Here is a very good making butter hands-on activity from the Scientific American) But even this experiment doesn’t really get down to the basic science of what is happening.  One of the Dairy Science pages comes out and says “exactly how churning works is unknown”.

So, while there is no definitive reference for exactly what is happening, here are a couple of aspects of the overall process:

1) Whole milk – whether from goats, cows, sheep or other mammal – is a complex mixture of water, proteins and fats. In addition, the mother is also providing other essential items including vitamins, minerals and enzymes.  (You can go to the Milk Composition Website to learn more.)

2) Milk that you purchase in today’s grocery stores have been pasteurized and homogenized. The pasteurization process requires the heating of the milk to kill the “bad” bacteria, i.e. those bacteria that cause illness in humans.  Homogenization is a physical process, by which the larger molecules, primarily fats, are broken down to allow them to remain in suspension.  If you can purchase milk from a local dairy, you may be able to find non-homogenized milk. Non-homogenized milk will separate into layers, i.e. a cream layer and a milk layer.  (This is a physical separation using gravity.  A commercial dairy uses a centrifuge to perform this separation and provides a milk with a consistent fat content. It is still a physical process based upon the density of the material.)

3) Milk can be considered a colloidal mixture.  A colloidal mixture is a fluid in which “particles” are suspended in a liquid, or dispersed throughout.  You can think of milk as being a mixture of water, butter fat particles, protein particles, etc. suspended and floating around in the container.  It is essentially, a liquid with very small solid particles floating in suspension.  This is a bit different than an emulsion.  An emulsion refers to two separate liquids, with droplets of one liquid floating in another liquid, for example oil and vinegar salad dressing.

So, what is happening when we make butter?

First, making butter requires “churning” or mixing of the cream. We have started with a physical separation of the butter fat into the cream layer and now have begun agitating it.  As the churning progresses, air is mixed with the cream to form a foam, i.e. air is trapped among the butter fat particles forming a stable suspension.  As the churning process continues, the “whipped cream foam” falls, i.e. the foam is no longer stable, because the butter fat particles have now begun to aggregate into larger particles and are no longer able to form the foam lattice.  The churning continues until large clumps of butter can be seen and collected using a strainer.

The entire process appears to be based on aggregation of the the butter fat particles by increasing the amount of individual interactions between the particles through physical agitation.  It is apparent that the collisions between butter fat particles under these conditions is inelastic, hence the aggregation of the individual butter fat particles.

Hopefully, this brief explanation will allow you and your aspiring kitchen helpers – to play with physics and enjoy the tasty result!

Boston Tea Party

Two hundred and forty years ago on December 16, 1773, there was an event in Boston.  It was a protest over taxes and triggered a number of cultural differences between England and what is now the United States.  In the US we have a coffee break – not a “Tea Time.”  

For many – this time of year is the beginning of a winter break – so how about starting another tradition?  Celebrating the Boston Tea Party – but having a Science Tea Party!

Here are some suggestions:

Want to keep everyone around the dinner table a bit longer?  How about a Tea Bag that floats in air?  (Note this demonstration uses fire – so needs to be done by an adult – but it is really cool!)  

Or a diffusion demonstration with a tea bag – or make a supersaturated solution – Southern Sweet Tea.

How about making a dye for paper or fabric? (For the paper you can make a treasure map.)

Finally – you can explore all five senses with this fun activity.

Have fun and be safe!

It is December already…..

You are probably in the throws of a busy holiday week – family, food, traditions, football, fun.  And – on Monday you will think – I can’t believe that it is December already.

If you are like most people – you try not to decorate for Christmas until after Thanksgiving.  If that is the case – then you can do some fun science to help decorate around the house –

Have you thought of a “Chemist” Tree?  You can do pretzel and gumdrop molecules.  Or do paper chromatography to create beautiful ornaments for the tree.

You can do some crystallization experiments – growing sugar crystals or growing Epsom salt crystals (NOTE: Parental supervision will be required.)  You can also make a solution of Epsom salt in water and “paint” on heavy card stock and let it dry – to form crystals on the paper – this is particularly good on red card stock as you make white crystal images.  (NOTE: you should not let children get the Epsom salt solution in eyes or drink the solution.  Goggles are recommended.)

Have Fun.