Materials in Our World

We recently started a new Science unit called Materials in Our World.  We have been specifically studying wood.  We have learned that wood comes from trees and many things are made from wood...at home and at school!  We have observed five different types of wood:  basswood, cedar, pine, particle board and plywood.  Basswood comes from linden trees.  Cedar comes from cedar trees and pine comes from pine trees.  Particleboard and plywood are types of man made wood.

In today's investigation, we worked with wood and water.  Our focus question for the lesson was "What happens when wood gets wet?"  We made some pretty good predictions and then set out to work!

First, we learned how to properly use eyedroppers...just like scientists do.  We got to practice with these and it was fun!

    

Next, we each got two samples of wood:  cedar and particleboard.  (These were chosen because water soaks into them at very different rates.)  Our job was to use the eyedropper and put drops of water on each wood sample.  Like real scientists, we made predictions about what we thought would happen first.  Then we added the water and observed...

   

We discovered two things...water changes the color of the wood and the cedar absorbed the water faster than the particle board.  Interesting!  Then we decided to see if the wood would sink or float in a basin of water.  Many of us thought they would sink, but some thought they would float.  There was only one way to find out...our helper placed a sample of each type of wood in the basin!

First the cedar...then the particleboard.

   

We were a little surprised to see that both wood samples were floating!  We decided to leave them for awhile and see if we noticed any changes.  At the end of the day, the particleboard appeared to be lower in the water, but neither sample had sunk to the bottom.  We are leaving the samples in the water overnight to see if that makes any difference.

So now we were very curious...what would make wood sink?  It must need to be heavy.  Next we tried some samples of plywood and pine.  Surely they would sink, right?  Wrong!  Now we had a plan...we added paperclips to each of the samples to see if the weight from the paperclips would make the wood sample sink.  We added five paperclips to each wood sample and attached them with rubber bands.

Only one problem...5 paper clips was not enough!  Then we tried 10 on each one.

   

10 paper clips made the plywood sink but not the pine.  So we added more paper clips to the pine sample...10 more for a total of 20!  Finally it sank, but it took twice as many paperclips as the plywood sample!  Wow.  We couldn't believe it!

Tomorrow we are going to change wood.  We are very curious about how we are going to do that, but Mrs. Kurt reminded us no worries in Kindergarten...she will teach us how tomorrow!