Friday, December 17, 2010

Melting


"Hey, who put water in here? This is just supposed to be ice."


"It's melting, Teacher Tom."


"When it gets hot ice melts and gets to be water."


"It doesn't feel hot in here. I'm wearing a sweatshirt."


"It's hotter than where is was before you put it here." 

"I guess so, it was in the freezer before."

"And the sun is shining on it. That's making it melt."



Then we started sprinkling it with rock salt, accelerating the melting process, slowly boring holes into our chunks of ice. We talked about how the teeny tiny things called molecules were moving faster as water changed from a solid to a liquid. Some of the kids seemed interested, but most were focused on injecting liquid water color into the rock salt induced holes and fissures.




We used the rock salt to fuse ice together.


It was an ever-evolving landscape of great beauty . . .



. . . exploration . . .


. . . and hands-on science.


Then we took it outside to learn what we could about it out there.


In the Pre-K class we continued to examine the concept of melting, starting with ice, then speeding up the melting process with an electric burner, converting it from a solid, to a liquid, then to a gas as we brought it to a boil. We then melted a yellow crayon and a little paraffin. We did the mental experiment of discussing what else we could melt, rejecting wood and paper because we knew they would burn. Most of us thought it would be impossible to melt metal, although Max thought we could if we made it "really, really hot."

We took a small lead figurine outside, put it in a spoon, then held it over a lit candle. It took awhile, but before too long we noticed the lead was liquifying around the edges. "It's melting! It's melting!" Once it started, the process of changing from a solid to a liquid went fast, leaving us with a spoonful of molten metal. In the meantime, some of them were too busy playing in the sandpit to be bothered with our experiment, but the kids who stuck around got to see me quickly pour the lead into a bucket of water where it instantly returned to its solid state, although in a new shape, one that Lachlan said, "looks like a sculpture."

Back inside, Lachlan asked, "Can we make the melted crayon back into a crayon shape?" 

As I explained that we would need a mold, I suddenly had an idea. "Let's try to make the crayon wax back into the shape of our metal sculpture!" So, as we re-liquified the wax, I grabbed a hunk of play dough, made a deep impression of our re-hardened metal in it, then poured the melted crayon into the depression, doing a sloppy job I might add, spilling it onto the rug. But the result was pretty impressive: a mirror image.


There is an Austrian tradition of melting these metal figurines on New Year's Eve, then tossing them into water. The resulting shape is supposed to tell your fortune for the coming year. We thought ours looked like the letter "L," which we all agreed stands for lucky.

Bookmark and Share

6 comments:

Barbara Zaborowski said...

Love it! Never tried melting a lead figure with the kids; must be time to try it, don't you think?

Juliet Robertson said...

Melting is just fun! I love the indoor-outdoor link here too.

I once spent an interesting day with my class who were determined to try and melt rocks. We boiled them, baked them and smashed them into tiny pieces. Nothing worked and the children began to realise just HOW hot volcano lava really is.

Michelle said...

We love ice exploration!! By far our favorite is the rock salt holes and colored water. I have tried to get them to notice how they can make a sculpture by fusing them together with water or salt... but they just are not interested in that part of the exploration yet :) Someday.

Plants seeds of knowledge...for our future! said...

I have had this activity in mind for me to do with my kindergartners. I love the tie in from indoors to outdoors. I do believe we will do the same! Where do you get the lead figures to melt? How long does it take? How hot does it need to be? What do I need to use for the heat source to melt lead. It looks interesting. I also think it would tie in lovely at the end of the year when we do our pioneer days!

Teacher Tom said...

@PSK . . . I got the lead figurines from a friend in Austria, although I'll bet they can be ordered online from somewhere. I don't know how hot it needs to be, but lead melts in a spoon held over a candle flame for about 7-10 minutes. We always do the lead melting outdoors. I worry about the fumes.

Shirley said...

It's a tradition in Finland also but they are horseshoe shaped figures. A special spoon with a long handle is heated over a burner on a stove and dumped into a bucket of water when it has melted. Then is the fun part of trying to 'read' your lump.

http://tin-mhjk.blogspot.com/

Related Posts with Thumbnails
Technorati Profile