Changes in Forms of Matter:


Crystals and Rocks :

observing... describing... sorting... making

What do YOU notice??

For a variation on this theme, check out our January Science 2012 page.Jan._Science,_2012.html

I start with ice crystals, because it is so natural for our “observtions of winter” to transition into the study of the various forms of matter.

My first question to the class is typically:

“what is the difference between snow and ice?”

During Reading Writing Workshop we fold our papers in half and write about snow on one side and ice on the other.  I’ve had my classes write about one of these topics:

what we like to do in snow and what we like to do with ice,

what we do on snow days vs what we do on ice days,

walking in snow vs walking on ice

We do a venn diagram comparing and contrasting snow and ice. All of our books about snow, ice, winter, polar regions, ice castles, winter sports, etc. are out during this study, both fiction and nonfiction. We graph our favorite snow activities. This year, we graphed our favorite Winter Olympics sport... what we’d like to try someday.

Later, we move on to:

How many forms of water do you see

around you in just one day?

How many of those forms do you use?

There are lots of “demonstration lessons.” (Demonstration because many of the lessons involve boiling water.) They observe and “take notes” (write down their observations) in their science journals because scientists have to learn to observe and to know how to write down what they observe. Scientists need to know how to use all kinds of charts, graphs, maps, and drawings. Science is one of those times when we almost always have to use “realistic” art forms rather than representational art. Although we do use representational art when doing graphs and charts... anything where it would be ok to use symbols and a key.

I let them observe melting ice. I show them how we can evaporate water by boiling it. I hold things over the steam to collect water droplets because some of them don’t believe that the steam is moist... humidity is a hard concept to grasp.

Just as ice crystals form due to a change in temperature, many other easy types of crystals can be used to demonstrate changes in matter.

When we make crystals in class we: change temperatures by either heating or cooling liquids. We change solids by adding liquid and then dissolving the solids, allowing the liquid to evaporate. 

(borax, epsom salt and alum all work well and are inexpensive)

Note: use medicinal grade alum - not the expensive baking alum!

We compare and contrast the 3 types of crystals that we make with all of the various crystals that we have out on display in class. 

Students often start bringing their favorite crystals and rocks to class to share, so quite a few of them even have their own little collections displayed on their nametags at their desks.

Next, we use all of our collections to compare crystals to rock... mostly volcanic rock because the kids are so easily fascinated with volcanoes and the various forms of rock that are made during a volcanic eruption.

This is where we get out all of my nonfiction books on: the earth, volcanos, crystals, minerals, landforms, matter, gemstones, jewelry, fossils, petrified wood...etc.

Learning about volcanoes is the perfect way to learn about all of the various factors that influence the formation of volcanic rock. All kids are fascinated by pumice and obsidian. The are also fascinated by the the unusual formations of places like Devil’s Postpile (Mammoth Lakes, CA.) 

Volcanic rock is also one of the easiest ways that I have found for students to practice applying the math concept of “sorting by 3 or more attributes.” During our forms of matter study we sort our various rocks and crystals into:

rock or crystal (we guess, then we check!)

smooth or rough

solid color or varigated color

translucent or opaque

heavy or light

red or brown or black or grey or mixed

sharp and jagged or smooth and rounded

Students take turns sorting rocks and the rest of the class works to figure out how those rocks were sorted.

As always, some classes become very interested in rocks and we continue to delve much deeper... Questions that our science investigations have led to in previous years are:

Why doesn’t all volcanic rock look the same?

Does volcanic rock look different depending on whether or not the hot lava goes into the ocean or onto dry land when the volcano erupts?

Are all rocks volcanic? What other kinds are there and how do they form? Are fossils rocks? Are gemstones rocks? What is the difference between rocks and minerals? Why are some rocks so much more expensive than others? Where can I get rocks? Is it always ok to just take rocks that I see? Why can’t I always just keep rocks when I find them?  How do gemstones get to be different colors? How did they dye these rocks? How do you cut rocks? How do you polish rocks?

Basically - this study can go on forever...

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