Conservation of Matter: Steel Wool & Vinegar

This is another versatile demonstration to use in your student of chemistry - learn about chemical changes, chemical reactions, conservation of matter and even air pressure.

Depending upon the take-home message you want your students to get, you might structure the activity in a few different ways, but the basics are the same.

You'll need some steel wool, vinegar, bottles or flasks and a balloon.

Pull apart some strands of steel wool and push some into each bottle.  Pour some vinegar onto the steel wool.  (Some instructions tell you to soak the steel wool in the vinegar for a few minutes and then remove the steel wool.  I just left mine in it).

Stretch a balloon over the opening of one bottle, but leave the other as is.

You could find the mass of each system at this point, if you're interested in conservation of matter.

Allow the bottles to sit and the reaction to occur. 

The vinegar removes the coating from the steel wool, and the steel will be begin to oxidize in the presence of oxygen. 

As the reaction is occurring, the balloon will be pushed into the bottle.  Why?

The oxidation reaction is using up the oxygen in the bottle, which will lesson the number of air molecules in the bottle, thus reducing the pressure in the bottle.  Because the pressure outside the bottle is greater than the pressure inside the bottle, it will push the balloon in. 

You can stop there if you're interested in simply looking for evidence of a chemical change, studying the chemical reaction or seeing the affects of air pressure. 

If you're interested in conservation of matter, continue on. 

Find the mass of each system once again.

The closed system (i.e. the one with the balloon covering the opening), should have the same mass it had in the beginning. 

The open system's mass should have gained mass, as it continued to pull more oxygen into the system to carry out the reaction further. 

Oceanic Acidification & Seashells

Birds and their eggs aren't the only animals for whom an increasingly acidic environment would cause great harm.  This simple activity demonstrates the effect of acid on shellfish.

You'll need a couple of shells (large or small, any variety, but for the sake of comparison, it's good to have two of the same), two cups or beakers, vinegar and water.

Place each shell in a cup/beaker.

Cover one shell with water.  You might want to use salt water, as these organisms live in the ocean, but I didn't think of that as I was setting things up. You could also do three shells at a time - one in vinegar, one in water and one in salt water.

Cover the other shell with vinegar. 

You'll notice that the shell in the vinegar immediately begins to form bubbles and fizz.  The vinegar is breaking down the calcium carbonate that composes the shell. 

Within 24 hours, you'll notice the shell that was in vinegar has holes in it.  If there was still a creature living in the shell, this could obviously be detrimental.

Vinegar, while a weak acid, is quite a bit stronger than acidified ocean water.  The stronger acid speeds up the process, making it visible within a short period of time - perfect for students to grasp an understanding of the process.  Shells in an acid ocean environment would be subject to the same chemistry, it would just take place at a slower rate.  

You can learn more about the chemistry taking place, as well as ocean acidification here.  

You may wish to continue to leave the shell in the vinegar for an extended time to observe further.  If so, it may be necessary to replace or replenish the vinegar.  (I used a small enough amount of vinegar that the chemical reaction came to a halt within a day or so).

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Remember to head over to Pow! Science! to check out their merchandise and put your Science Matters discount to use!  Details can be found here.  

Cookie Fossil Dig

Can your students work with the precision and patience needed by a paleontologist on a fossil dig?

Provide each student with a chocolate chip cookie, a toothpick and a small paintbrush.  See who can remove the most unscathed chocolate chips without breaking the cookie!

You might want to have your students try a few different types of cookies - are the chips easier to remove from crisp cookies or soft, chewy cookies?

I did this simple, paleontologist cookie dig with students at our library during a summer program, which was perfect for the age group I was working with (3 - 10).  However, I've also done cookie mining with middle school students.  Women in Mining provides a fantastic activity that includes a financial aspect (students are given a budget and have to purchase their cookie, mining tools, mining time and reclamation costs) in addition to precision.  I've mentioned it before, but it's worth repeating... take some time to check out the other activities on the Women in Mining website - they're really well done!

New School Supplies and Pow! Science!

I don't know about you, but one of my favorite parts of a new school year, in addition to a fresh start full of possibility, is all of the new "stuff" that goes with it.  Brand new pencils and pens.  Fresh notebooks that don't have a mark in them (unless one of my children has gotten to it before me....).  Perfectly clean glassware.  Replacement supplies for your favorite demonstrations and labs.  Science "toys" that you know are going to capture your students' interest.

Seriously.  Does anyone have any more fun spending their classroom budget than science teachers?  Maybe art teachers.... Maybe. 

I've got a fairly-new-to-me source for some fun and educational science supplies: Pow! Science! (Great name, right?)

Their prices on glassware (beakers and graduated cylinders) are very competitive.  (It's even better when you add on a Science Matters discount.  That's right!  Read on, my friends). And it's real glass!  I really dislike plastic beakers.  It's okay for graduated cylinders, but real glass is still so much better.  The selection and quantities are limited, so it's likely not the place to go if you're looking to outfit a whole science department.  But, if you're looking for some real glassware to use in your home laboratory or a few pieces to add to your individual classroom, I highly recommend you take a look. 

Some other "basic" supplies you might be interested in:
Litmus and pH Paper
Eye Droppers
Magnifying Glasses
Magnets

And then there's the stuff that's a little more fun...

Snap Circuits

Hand Boilers

Thermal Expansion Ball and Ring

Now for that discount...

Pow! Science! is offering Science Matters readers a 15% discount on their entire purchase!through September 30.  Simply use the code SCIMATTER0913 when checking out.  There's no minimum purchase required and you can use the code as many times as you like.  

 

So, shop and shop often! 

 

Kick off that new school year in style!  Or if you're all set for the school year, why not get a jump on some holiday shopping for the scientists in your life.... :)

 

One more thing... if you live near or happen to be visiting the Rhode Island vicinity, you can visit their brick and mortar store.  Also, check out their programming: free Lego days, birthday parties, homeschool and scout presentations and so on. 

AMS Graduate Credits

It's been almost 2 years since I first told you about the DataStreme courses. 

I was so excited to find these courses that were largely completed online and had the possibility of earning 3 graduate credits for no cost.  But, at that point I could only tell you what I'd read about and heard from the one woman I'd talked with.  I fully intended to write a follow-up post, but never quite got to it... Better later than never, right....?

First, a quick synopsis -

The American Meteorological Society offers three DataStreme courses:

DataStreme Atmosphere,

DataStreme Ocean

and DataStreme Earth's Climate System.

This is a nation-wide program for K-12 teachers.  The courses are sponsored by AMS, NOAA, NASA and NWS.  When accepted as a participant, your books and graduate credits are completely funded.  The credits are granted by the College at Brockport SUNY. 

The courses are largely conducted on-line using real-time data.  You will need to travel to a class-site 3 or 4 times per course, to meet with the instructors and other students. 

Now, my experience...
I enrolled in the Earth's Climate System Course in the spring of 2012.  Filling out the application doesn't ensure a spot in the course, but I don't think there was a whole lot of competition for the spots, at least in my area.  I've been told that preference is given to people taking their first DataStreme course (though there were people in my class taking their second or third one). 

I had to drive to Albany for 3 in-person meetings.  It's a little more than an hour drive for me, which is certainly reasonable since I have to drive nearly that far to get to almost anything!  There were people in the class who came from much further - 2 or 3 hours away.  It's a long way to go, but if you figure the cost of 3 graduate credits and the time/cost of driving to a conventional, local class 12 times during a semester, I think you come out ahead. You come out even further ahead if you can convince a colleague or someone who lives near you to take the course at the same time as you so you can carpool! 

No textbook in this picture because when I went to quickly snap this pic, the textbook wasn't where it was supposed to be.  Of course. 

The first meeting was held before the class really started.  We were given our materials - a textbook, a workbook and a large binder filled with course information as well as the weekly homework questions (all in a canvas tote bag).

There's the textbook.  From the AMS website.

Each week's work consisted of textbook reading and answering associated questions, 2 "labs" in the workbook (a lot of these involved looking at and interpreting data), and some current reading (found on the website) with a few questions.

My class's instructor encouraged us to brainstorm ways in which we'd use the information used presented in the lesson in our classrooms, and include that with our homework each week.  This additional step made it simple to pull together our final projects as the semester wound down. 

Our class submitted our weekly homework to instructors via email.  Fax options may be available in some situations. 

Final projects consisted of writing an action plan outlining the ways we would use the course information in our classrooms and ways in which we would share what we've learned with other teachers around us.  We each gave a brief presentation highlighting the information in our papers. 

During the final meeting of the semester, we gathered to share our final projects, complete course evaluations and fill out the final paperwork in order for SUNY Brockport to award our credits. 

Our class had a third in-person meeting in the middle of the semester.  Unfortunately the weather didn't cooperate and the meeting had to be rescheduled, causing several members of the group to miss out.  And they did miss out... our group met at the National Weather Service forecasting office.  We were given a tour of the office and learned what the forecasters do on a daily basis, and we were able to watch them launch one of their two-per-day weather balloons.  There was lots of freedom to ask questions and take in as much as possible.  Equally valuable was learning about the opportunities available for our students - possible guest speakers, field trips, etc.  I obviously can't speak for everywhere, but the people in this office were very interested in outreach and working with students.  It was a fantastic experience. 

I really enjoyed the class and learned a lot.  I had the flexibility to do the work on my own time, when it was convenient, but also had the benefit of instructors who were readily available via email and phone to answer questions and help explain information that was challenging.  The course wasn't overly difficult but there were some challenging concepts to try to wrap one's brain around.

I'm looking forward to taking the other two courses at some point in the future.  It will be a bit more of a commitment, as the other two are not held at locations as near to me, but when the time comes, I will make it work! 

If you have any further questions about the courses or would like help registering, let me know and I'll be glad to lend any assistance that I can. 

Let Us Weigh Lettuce

An easy lesson in measuring mass, collecting data, graphing (if you wish), percentages and plants. And a great experiment to start at the beginning of the school year.

You'll need a leaf of lettuce and a balance.  The precision of an electronic balance is nice for this particular activity, if you have one available.

If you have a balance that can remain dedicated to this activity, you can place the lettuce leaf right on it.  Record the mass.  Each day when the students come to class, they should record the mass of the lettuce.  Continue recording the mass every day for a month.

[If you cannot dedicate a balance to the activity, you'll need to first find the mass of a weighing paper.  Record that, then place the lettuce on the weighing paper and record that mass.  Lift the paper with the lettuce on top and keep in a safe place while the balance is being used elsewhere.  Return the paper and lettuce to the balance each day to find the mass.  You'll have to subtract the mass of the weighing paper from each measurement to get the mass of the lettuce.]

Once you've collected all the data, you can graph it if you wish.  Is the water lost at the same rate throughout the month or does it change?

You can also determine how much of lettuce (by mass) is water.

Mass of lettuce at start - Mass of lettuce at end = Mass of water

(Mass of water / Mass of lettuce at start) * 100 = % of lettuce mass that was water

If you've caught your students' attention with this one, you can proceed to follow the same procedure to find the water content in other items.  Maybe your students will want to compare the water content in different types of lettuces or different types of leaves or different types of fruits or vegetables.  Lots of possibilities - you could have something going every month of the school year!

Erosion & Run-Off: What affect does vegetation have?

 This is a really simple demonstration, but it does require some planning ahead (not always my strong suit... )

You'll need two shallow pans or boxes.  Fill each pan with dirt.  Sprinkle grass seed on one of the pans of dirt.  Keep the soil moist as the grass seed germinates and grows.  (You don't need to do anything with the other pan of dirt right now).

Once you have a nice crop of grass in the one pan, take both pans outside.  Prop up one end of each pan using bricks (or something else that will raise it a few inches).

Begin to spray both pans with a hose or spray bottles of water.  You can spray in any manner you'd like, just try to get both pans equally.

While you're spraying, observe what happens to both the soil and the water in each situation. 

When you've finished, discuss the impact of vegetation on soil erosion and/or water run-off.