Wednesday, April 16, 2014

Coming Next Week: Top 10 Household Products to Use in Your Classroom

I'm jumping back into the blogging world with a special-two-week event and a contest!

I've always proclaimed myself to be a hands-on science teacher who relies heavily on readily available household items to carry out experiments.

These are items that are always kept close at hand, because as soon as they get put away, they're needed again.  Sometimes it's for a planned lesson, other times you pull them out to help answer a question as it comes up.

At various times throughout my time authoring this blog, I've debated which of those items I'd place at the very top of my list.

So, this week I'm going to do a Top 5 list.  Each day I'll reveal a favorite product and I'll share links to a plethora of activities/experiments you can carry out using said product.

If you leave a comment, you'll be entered to win a prize pack containing most of the Top 10 items (one or two of them may not be appropriate to ship...).  You'll get a bonus entry if your comment includes another way to use the item in a science classroom!

I'll see you on Monday for #10!

Tuesday, January 7, 2014

Nursery Rhyme Science: Hot Cross Buns

Hot cross buns!
Hot cross buns!
One a penny, two a penny,
Hot cross buns!
Give them to your daughters.
Give them to your sons.
One a penny, two a penny,
Hot cross buns!

Activity 1: Rising Up
Hot cross buns are a type of yeast bread.  Yeast is a living organism (a fungus to be exact), that is used to make bread dough rise.  If you didn't use yeast, your bread would be small, flat and hard as a rock.

When you open a package of yeast and pour some out, it doesn't look like much.  It certainly doesn't seem to do anything.  The yeast is in a dormant state - it's still alive but it's not actually doing anything; kind of like being asleep.

To get the yeast going you'll need to do two things:
1 - warm up the yeast so that it "wakes" up
2 - give the yeast something to eat

Put the yeast in a flask or small-neck bottle.  Add some warm water (to wake up the yeast) and some sugar (to feed the yeast).

Stretch a balloon over the top of the flask/bottle and allow it to sit somewhere where everyone can keep an eye on it for the next hour or two.

As time passes, you'll notice the balloon filling up.  It's catching the carbon dioxide the yeast is releasing.  When you make bread, the yeast does the same thing, creating small pockets of air within the bread!

Activity 2: Does "Hot" Always Feel the Same?
 Temperature can be a funny thing.... A 60 degree day in March feels fabulously warm and wonderful.  That same temperature, in the middle of July, feels frigid.  The temperature is the same, but the way in which it feels can vary depending upon our perspective.

Here's a way you can actually feel that principle at work in a matter of minutes.

You'll need three bowls:
--Fill one bowl with water and allow it to sit for about 5 minutes (or more) to reach room temperature.
--Fill the next bowl with water and add several ice cubes.  Stir.
--Fill the final bowl with warm tap water.  Aim for something that just feels warm on your wrist - you don't water so hot that it'll hurt you.

Arrange the bowls on the table so that the room temperature water is in the middle and the hot and cold water are on either side of it.

Place one hand in the warm water and the other hand in the cold water.  Leave them there for about 20 seconds. 

Remove your hands from the bowls and place them both in the middle (room temperature) bowl.  How do they feel?

Even though they are now in the same water, the hand that was in the cold water feels warm and the hand that had been in the warm water feels cold.

The explanation....
You placed your hand in warm water.  The energy (heat) moved from the water, which was hotter than your hand, to your hand, making it feel warm.  Then you placed it in water that was colder than your (now warmed) hand.  The energy (heat) left your hand and flowed into the water, leaving your hand feeling cold.

You placed your other hand in cold water.  The energy (heat) moved from your hand into the cold water.  When you placed that hand, with a reduced amount of heat energy, in the room temperature water, energy (heat) flowed from that water to you hand because there was more energy in the water than your hand.

Monday, December 30, 2013

Snow Science

If you've got antsy kids at home and another week of vacation time to fill, here are a few more ideas to keep them busy, having fun and learning!

Activity #1 - How Much Water is in Snow?

If you're finding yourself with an abundance of snow.... perhaps you'll want to perform some investigations. 

The amount of water snow contains can very greatly, depending upon the snow. 

Gather a set amount of snow... I collected approximately 500 ml of snow.

Allow the snow to melt - if you'll be allowing it to sit for an extended time, you may wish to cover it to minimize the amount lost to evaporation. 

My 500 ml of snow yielded slightly less than 50 ml of water.  This was a very dry, powdery snow. 

If you live in a place that gets snow throughout the winter, you might want to repeat this activity with each snowfall and see how they vary in water content.

Activity #2 - Learn About Snowflake Bentley

Wilson Bentley was the first man to photograph individual snowflakes, in 1885.  He's the person who determined that no two snowflakes are exactly the same.  A fascinating man, indeed.

Start your research at the Official Website of Wilson A. Bentley.  You'll find a brief biography there, and some wonderful, printable images of his photographs. I printed
 out the collection and laminated them for my students to look at and admire.

Snowflake BentleyFor a more thorough biography, and one to share with your students, check out Snowflake Bentley.  It's a picture book intended for children.  The biography is written as a story, with a lot of factual information in the margins - you can decide how much to share based on your students.
The Snowflake Man: A Biography of Wilson A. Bentley

For your own knowledge, you may want to read The Snowflake Man: A Biography of Wilson A. Bentley.  I haven't read the whole book, but have read an excerpt.  You can probably get it through your library system.

Two other books that look interesting are Snowflakes in Photographs and Snow Crystals. I'm not familiar with either book, but they are both collections of Bentley's images.  Again, it might be worth looking for these at the library before investing.
Snow Crystals (Dover photography collections)Snowflakes in Photographs

Activity #3 - Make Sparkly Snowflakes
This is a fun, artsy-craftsy project in which students can learn about solubility, super-saturated solutions and crystal shapes.

Make a super-saturated solution of Borax and water:
--Fill a jar with hot water (boiling is best).
--Add Borax, a little at a time, until no more will dissolve (you'll know you're there because instead of dissolving the Borax will settle to the bottom)

Use pipe cleaners and thread to make a snowflake.

Attach a piece of thread to the snowflake.

Place the snowflake in the Borax solution and leave for several hours or overnight.

In the morning, you'll have a beautiful, sparkling snowflake, covered with large crystals.

If you'd rather not make snowflake shapes, you can shape the pipe cleaner into stars or other shapes.  You could also just place a straight pipe cleaner into the solution.

The pipe cleaner works well because all the fuzz on it gives the crystals nice places to attach, and thus works much better than just a string.  (Which may explain why all my attempts at making rock candy as a kid were met with utter failure (and a sticky mess)).

Safety Note: The Borax and the finished snowflake should come nowhere near the mouth.

Activity #4 - Learn About the Coldest Places on Earth!

Check out the National Snow & Ice Data Center, where you can learn more about some of the coldest places on Earth!  There are lots of neat pictures in the photo galleries

Monday, December 23, 2013

Hot Chocolate Science

Here are some seasonal science ideas - perfect for a long, cold vacation day with your own kids, or when your school kids need something fun to break up the sometimes-long stretch that is January and February.

Activity #1 - Hot Chocolate Solubility
You'll need at least two different varieties of hot chocolate mix and one mug for each variety.

Place an equal amount of mix in each mug. Add the same amount of water to each mug (it would be good if you could have one person add it to each mug, so it all gets added at the same time). Stir the contents of the mugs (at as close to the same rate as possible), and observe.

Does one variety dissolve better (faster) than the others? Hypothesize what makes the difference.

Activity #2 - Hot Chocolate Taste Test
Since you acquired a few different varieties of hot chocolate for activity #1, you might as well put them to additional use....

Before you prepare the hot chocolate, create a list of properties you find desirable in hot chocolate, as well as those less-desirable.  Possibilities include: sweetness, chocolatey-ness, creaminess, bitterness.

Prepare each variety of hot chocolate according to its directions.

Sample one variety at a time and evaluate it on the properties you listed, giving it a score for each property.

Once you've sampled and evaluated each variety, analyze the results to see which properties your favorite hot chocolates have in common.

Activity #3 - Are Marshmallows Good Insulators?
Prepare two identical cups of hot chocolate (same variety of hot chocolate, same amount of power, same amount and temperature of water) in identical mugs.

Float enough marshmallows on the top of one of mugs to completely cover the surface.

Place a thermometer in each mug.

Observe and record the temperature of each mug every few minutes.

Do you notice any difference between the two mugs?  What do you think accounts for that difference?

If you're looking for some additional activities.... 
the Sugar Cube Rate of Solution activity and the Goldilocks & the Three Bears Heat Transfer activity could both be adapted for use with hot chocolate. 

Tuesday, December 17, 2013

Nursery Rhyme Science: Humpty Dumpty

Humpty Dumpty
Sat on a wall.
Humpty Dumpty
Had a great fall.

All the King's horses
And all the King's men
Couldn't put Humpty
Together again.

Activity 1: Safe From Any Height
Host a mini-egg drop contest to see what could be done to protect Humpty Dumpty.

Before students get to work, demonstrate what happened to Humpty Dumpty in the rhyme.  Push a raw egg off a desk (onto a drop cloth or something else that will make clean-up easier) and observe. 

Put students into small groups to work and challenge them to build a contraption to protect Humpty Dumpty from any subsequent falls.  With preschool or kindergarten students, I would provide each group with a cup or other container as a starting point for their construction.  I wouldn't give anything to older students - let them come up with the ideas on their own. 

Provide an assortment of additional materials for students to work with:

  • yarn
  • fabric
  • packing peanuts
  • sponges
  • cotton balls
  • newspaper
  • balloons
  • straws
  • popsicle sticks
  • cotton batting
  • anything else you can think of

After students have completed their contraptions and placed an egg inside, push each one off the same desk and see if Humpty Dumpty fares any better.

It's possible that some eggs may still break, which is the perfect time to ask the students how they would change their contraption design to make it even better. 

Tuesday, December 10, 2013

Nursery Rhyme Science: Little Jack Horner

Little Jack Horner sat in a corner,
Eating a Christmas pie.
He put in his thumb,
And pulled out a plum,
And said, “What a good boy am I!”

Activity 1: Identify the parts of a plum
It's very possible that your kindergarten students aren't familiar with plums.  Pick one up at the store and identify the parts with them: the skin, the flesh and the pit.

Activity 2: Compare and Contrast
Compare the plum to another fruit that students, such as an apple or an orange.  What do the fruits have in common and what's different about them.

Activity 3: Plant the pit
Will the pit grow?  Remove the pit from the plum and plant it in a cup with some dirt.  Give it a little water and see what happens.

Tuesday, November 12, 2013

Nursery Rhyme Science: Hickory Dickory Dock

Hickory Dickory Dock,
The mouse ran up the clock.
The clock struck one,
The mouse ran down.
Hickory Dickory Dock.

Activity 1: The Chiming Clock
Can you make a coat hanger sound like a loud, chiming clock?

This is a simple demonstration that helps make the point that sound needs something to travel through and that air is not a very efficient material for that purpose.

You only need a wire coat hanger and a long length of string.

Tie the string onto the hanger, so that the hanger hangs from the middle of the string.

Swing the hanger from the string so that it bumps into something (a table, chair, wall, etc.) and take note of the sound it makes.  It's kind of a short, clang-y sound.  Nothing very dramatic or melodic about it.

Now, wrap one end of the string around one of your index fingers and the other end around the other index finger.

Place your fingers in your ears (gently, there's no need to jam them in).

Swing the hanger so that bumps into something once again and take note of the sound it makes.  Louder and more like a gong or large bell ringing.

In the first trial, the sound made when the hanger hit the object had to travel through the air to reach your ear drum.  A lot of the sound was lost on the way to your ear.  In the second trial, the sound vibrations travel from the hanger through the string and your fingers to your ear.  Much less sound energy is lost in route and it makes an audible difference.