Have you ever taken apart your toys and put them back together in new ways?  Of course you have!  You are a scientist.  Like a big toy box, the Earth is also filled with many small parts that come together and break apart to make new things.  Unlike your toy box though, it almost never loses anything or gets any new parts.  The world is very responsible with its toys.  If you call ripping them apart responsible . . .

Just like your toy box, the world has its own building blocks.  Atoms are the very small building blocks that make everything you see around you.  From trees to tires, from your hand to a horse hoof, from your action figures to the Statue of Liberty, atoms build them all.  These building blocks are very small, though.  If you lined up one million of them, they would only be as wide as one of your hairs!  It's a good thing you are not responsible for keeping track of those building blocks.

Just imagine how many atoms it took to make the Statue of Liberty.

These building blocks come together in all sorts of ways to make everything you see.  A compound is when two or more different atoms come together to make something new.  You might pull the head off of a doll and put it on the body of a toy t-rex or have an alien make something in an Easy Bake Oven.  With atoms, two H's will come together with an O to make water!  If that does not sound as fun as a dinosaur with a doll head, then clearly you have never been on a water slide.

Just imagine how many atoms it took to make the Statue of Liberty.

Of course, when you change parts on one thing other things change too.  You need to use your energy to switch around your toys, putting another arm here, a cow tail there.  A chemical reaction is what happens when two atoms come together or break apart to turn into something new.  When this happens, the reaction can let out energy, getting hotter, or take in energy, getting colder.  That's like when your little brother lets out energy with a scream after he sees what you have done to your toys.

You can stop his screaming, though, by putting the toys back the way they were.  You still have all of the pieces.  None of them went anywhere.  The world always has all of its atoms too.  Conservation of mass means that no matter what changes, the amount of stuff there stays the same.  There is never any more and there is never any less.  This means if I break apart some water into two gases, there's still the same amount of "stuff" there.  It just looks different.  Even if you lose a doll head or a monster eye or a car wheel, they are somewhere out there . . . scaring the heck out of someone.

The world is not so different from a toy box.  Toys have parts and the world has building blocks like atoms.  These can fit together, come apart from each other, and be put back together to make new things; just as you pull your toys apart and build other things with them.  A chemical reaction is when these parts change into something new, which will make heat or will take away heat.  No matter how much stuff is pulled apart and put back together, the amount of stuff always stays the same, so you and the world will always will have these toys and atoms to play with.


Ducksters.  "The Atom"  Ducksters, 2011.  <http://www.ducksters.com/science/the_atom.php>