Sunday, October 31, 2010

Goop: Is it a solid or a liquid? It is a suspension!

The day started with the grinding of chalk into water and the question: "How much chalk would I need to make this mixture solid?"

Which reminded me of Goop.

Ah goop.  Noor was first introduced to this marvelous substance a few years ago by the parents' of her now best friend.  I believe they made a tub of it that was large enough to stand in.  We didn't go that large-scale, but Noor went through two boxes of cornstarch in a flash.


1 Cup cornstarch
1/2 water with a few drops of food coloring--add slowly to the cornstarch and stir.

We talked about states of matter, atoms and molecules and about how cornstarch, which is made of loooong chains of molecules is a polymer.  Goop acts like a solid when it is pressed together in your palm because the molecules are really close together--the chains get entangled.  If you relax your grip on the goop, it flows like a liquid because the chains of molecules have space to move around each other.

Noor added more and less water to subsequent batches, made some inside a plastic bottle and experimented with how shaking and pouring effected the suspension.

It was clear she was working through a deeper understanding of the states of matter when later that evening, she told me that ghost are a gas.  "Why," I asked.  "Because their molecules are really far apart, which is why they can pass through walls."


Friday, October 22, 2010

The Layers of a Banana's Skin

It was vaccination day at the pediatrician's yesterday and this morning Noor asked how far her muscle was below her skin, because it is her muscle that hurts at the vaccine site and not the skin itself.

She decided, after we looked at some images and did a bit of reading, that she could see what was going on inside her arm by poking various pieces of skinned fruit.

She says she feels more like a banana than an orange.

Tuesday, October 5, 2010

Sunday, October 3, 2010

Iron Hill Museum

Noor and her best bud spent the day in a private class at the Iron Hill Museum, which is housed in a one-room schoolhouse that was the "former Iron Hill Public School 112-C, built in 1923 as one of more than 80 schools for black children and given to the state by philanthropist Pierre S. du Pont."

Drivers who speed down I-95 past Iron Hill probably never imagine:
George Washington stood atop the hill and spied on the British on Aug. 26, 1777:
Minqua Indians raided Lenni Lenape villages there in 1661.
The governor of Pennsylvania operated an iron forge there in 1725.
The yellow, one-room schoolhouse there houses a stuffed brown bear, mosasaur bones, a whale's shoulder bone, a 10-million-year-old extinct oyster shell and live Madagascar hissing cockroach babies born last summer. 
Iron Hill, now a quirky wonderland for children interested in science, has had more past lives than Shirley MacLaine. It was an American Indian mining site. British troops pitched their tents there in 1777. Caesar A. Rodney, nephew of the signer of the Declaration of Independence, led an encampment of American troops there during the War of 1812. P.S. du Pont built a state-of-the-art African-American school there in 1923.
What mineral first drew American Indians to Iron Hill? The answer isn't the no-brainer you expect. It was jasper, not iron ore, that drew them to Iron Hill in the 1600s and possibly earlier. Archaeologists believe they quarried the hill's jasper, a sharp-edged variety of quartz, and made it into tools on-site. The evidence: They found thousands of jasper chips leftover by the toolmakers.  (Kathy Canavan, Special to the News Journal)
Noor and Roman were treated to a tour of the museum and then they settled in to talk about the geology and geography of the area.  A trip to the old mine provided the opportunity to identify jasper and quartz.

Saturday, October 2, 2010

Dragon Tanagram

All the different shapes that can make up a Chinese Dragon: