Wednesday, September 8, 2010

Plants: Roots: Radish Seedlings

Radishes are perfect for this... they sprout and develop roots SO quickly!

About 3 or 4 days before you'll need them, sprinkle some radish seeds on a damp paper towel.  Keep the towel moist (a spray bottle with a fine mist is good for this) in the interim.
  

On lab day, have students observe the radish roots.

What is the fuzz on the root?
What does it do for the plant?
Draw the seed and developing root - label the first leaves, devleoping root, and root hairs.


A few notes, from personal experience
--Keep the radish seeds covered with another damp paper towel.
--Keep the seeds in a place where you will see them so you will keep them moist - they will need water a couple times a day - they dry out super quick!
--Be very careful when removing the seedlings from the paper towel - it doesn't take much for the root to break off. 

Tuesday, September 7, 2010

Plate Tectonics: Moving Continents

This activity demonstrates how the tectonic plates move on the asthenosphere.

Prep Work:(check out this post, for more information on the gak/putty used in this activity)
Create a solution by dissolving Borax in water. Place a small amount of this solution into a small cup (one for each pair of students). Place a small amount of diluted white glue into another small cup (one for each pair of students).

The Activity:
Each pair of students is given a small (roughly 3”x5”) piece of fun foam. The foam is cut into two pieces – it can be cut in curving or zigzagging lines, but the pieces should not interlock.

Students create the asthenosphere “putty” as follows:
-Obtain two cups – one containing a small amount of glue, the other containing a mixture of Borax and water.
-Pour the Borax mixture into the glue cup
-Stir the mixture using a straw
-After stirring, pour the excess water into the sink
-Knead the putty with your hand for several minutes, until it is no longer sticky

Place the putty onto a plate and pat it into a pancake.

Place the two pieces of foam onto the putty, making sure the cut edges are right next to each other.

Observe your foam pieces for the next five minutes. Draw what occurs at each one-minute interval. Label the distance between the two pieces of foam on each drawing.

Monday, September 6, 2010

Density: Float an Egg

What happen if you put an egg into a container of water? 
It sinks.

How can you make it float? 
You need to make the egg less dense or the water more dense.

I don't know how to readily change the density of an egg, but I do know how you can make the water more dense: SALT. 


Start adding salt a tablespoon at a time.  It takes a bunch of salt, so don't give up.  Eventually, there will be enough salt dissolved in the water and the egg will float. 



*****
A Note:
Don't be all fancy and use kosher salt.  Regular old salt works better - the smaller size makes it dissolve easier. Go ahead, ask me how I know (and then look at the picture above to find the answer).

Friday, September 3, 2010

AIMS: Magazine and Lessons

AIMS Education Foundation is an organization aimed at giving students a solid understanding of math and science. 

For awhile I maintained a subscription to their magazine.  It's a beautiful, high-quality publication.  I did let my subscription lapse... I found it to be a bit expensive and I felt like there were more lessons geared toward math than science in the editions I received (that may have just been a function of that particular year, or just something I imagined, but regardless, it just wasn't meeting my expectations).  However, I do know that they have produced some great activities, that I've come across through other resources (and thus my interest in the magazine). 

Even if you're not interested in the AIMS publications... head to their website - they have several of the activities available as free samples.  There aren't a lot, but you might find something of use to you.

There are also some downloadable activities that are available for a dollar or two each.

Thursday, September 2, 2010

Chemical Changes: Gak

Prep Work:
Create a solution of Borax in water. Pour a small amount of the solution in small cups (one for each student or pair of students).

Dilute some white glue with water, 1:1.  Put a small amount of the diluted glue in small cups (one for each student or pair of students).

Activity:
I use this as an introduction to chemical changes, so students don’t really have any background information.

Provide each student/pair of students with a cup of the Borax solution. They should document any observations they can make.

Provide each student/pair of students with a cup of glue. They should document any observations they can make.

Ask students to predict what will result if the contents of the two cups are combined.

Pour the Borax solution into the glue cup.

Stir the mixture using a stirring rod, popsicle stick, or straw.

After stirring, pour the excess water into the sink.

Knead the gak with your hands for several minutes until it is no longer sticky.

Document any observations that can be made about the putty.

Discuss the ways in which properties of the gak differ from those of the initial substances.

**Borax should be no where near student's mouth or eyes.  Wear safety glasses and wash your hands thoroughly after doing this activity.  If you can't trust your students not to drink the Borax solution, don't do this activity.

Wednesday, September 1, 2010

Animal Adaptations: Baby Birds

Here's a game for younger students learning about animal adaptations.

Divide students into group - you'll want 4 or 5 students per group.  Select one student in each group to serves as the mama/papa bird; the rest will be baby birds.

The mama/papa will be responsible for going to the food supply (a plate of pretzel sticks in the middle of the classroom), bringing back a piece of food and feeding it to the loudest baby bird.

The baby birds will be responsible for squawking loud enough to get fed ahead of their bird siblings.


Play the game for several minutes - be prepared for a very loud classroom!

Then, talk about what happened - the birds who squawked the loudest got the most food.  These birds will grow big and strong and some day have baby birds of their own - probably babies who are loud squawkers.  The babies who didn't get as much food to each might not fare as well. What might happen if a baby bird is born and unable to squawk at all? 

While squawking volume is not, to my limited knowledge, a trait that is regularly selected for, this game does introduce the ideas of adaptations, genetics, and trait selection to young children in a context they can understand.

******
Idea from Anna McGhee, with many thanks!

Tuesday, August 31, 2010

Acid Rain and Baby Birds

Vinegar is a weak acid.  It's much stronger than acid rain, but it can be used to show the effects of acid rain over time.

One effect acid rain has is on baby birds.

Soak an egg in vinegar during the course of the school day, or overnight.

You will find that the shell dissolves in the vinegar.

While acid rain is not strong enough nor does it act over a long enough time to completely destroy the shell, it does weaken it.  This allows pollutants to potentially enter the egg, as well as reducing the baby bird's protection.