Body Systems: Nervous System: Brain Model

The human brain, at full-size,  is about the size of a full sheet of newspaper (or a pillow case), that's folded up to fit in your skull.

Keep your eyes open for a sheet of newspaper that has a full page ad that has some writing, but a large white space.  When you're born, your brain already has a lot of information stored in it, represented by the writing on the page.  But there's also a lot of room to learn more.  That's the white space on the paper - the brain space that's left to "write" on.
 
It's difficult to put numbers on how "full" one's brain is at birth and how much "room" there is for future learning, as the more you learn the more connections your brain makes.  It appears that there's always room for more learning to take place and that the brain is never "full" (to our current knowledge). 

Compound Story

Have your students write some "science fiction".  

Each student chooses a compound (see below for some ideas) about which to write a story.  While not a report, the story should include scientific information about the compound and include the compound's empirical and structural formulas. 

Encourage your students to be creative in their writing and get into character - they could tell the story from the compound's point of view.  They could "be" one of the elements within the compound.  They could be reporting on a big news story involving the compound. 


If students are having a hard time getting started, they may want to look up their compound to find out what it's used for and where it's found - what they learn may be the start of a story. 

To make sure students don't get too carried away with the fiction aspect and forget the science part, you might wish to require them to use 12 (or whatever number you deem suitable) science terms.  Some possibilities:

• metal
• nonmetal
• solid
• liquid
• gas 
• chemical change
• physical change
• compound
• mixture
• periodic table
• family(ies)
• atomic number
• atomic mass
• stable
• unstable
• positive
• negative
• neutral
• valence electrons
• valence number
• empirical formula
• structural formula
• subscripts
• octet rule
• arms
• giver
• taker
• bonds
• share
• scientific name
• react
• reaction
• atom
• molecule

A list of compounds, to get you started:

• methane
• ethane
• propane
• butane
• octane
• acetylene
• benzene
• toluene
• carbon tetrachloride
• methanol
• ethanol
• propanol
• butanol
• carbon monoxide
• carbon dioxide
• calcium bicarbonate
• calcium oxide
• hydrochloric acid
• carbonic acid
• nitric acid
• water
• hydrogen peroxide
• hydrogen sulfide
• sulfuric acid
• ammonia
• nitric oxide
• nitrous oxide
• sodium chloride
• sodium nitrate
• sodium bicarbonate
• sodium hydroxide
• ozone
• silicon dioxide
• fructose
• sucrose
• potassium chloride
• citric acid
• vitamin C
• silver fluoride
• sodium fluoride
• silver chloride

The Expanding Universe: Balloon Model

 On a flat, not-yet-inflated balloon, mark a series of points using a permanent marker.  You may wish to make some of the points closer together and others farther apart. 

These marks represent parts components of the universe.  You may wish to have students measure the distance between points to make it more quantitative, of you may wish to just keep it a visual activity. 

 As you begin to inflate the balloon, the points mover farther and farther away from each other.  The universe is expanding and distance between points is growing. 

Rate of Reaction: How Does Surface Area Affect the Rate of Reaction?

 The combination of Alka-Seltzer and water produce a chemical reaction.

To see how surface area affects the rate at which this reaction takes place, you'll need two Alka-Seltzer tablets and two glasses of water. 

 Keep one of the tablets intact and crush the other tablet (crushing it into an actual powder would be even better than the pieces I've shown here - good chance to break out the mortar and pestle if you've got them).

Drop the whole tablet and the crushed tablet into the water (each tablet into its own glass of water) and observe the length of time it takes each reaction to finish. 

Cells: The Importance of Cell Walls

 Cell walls prevent plant cells from bursting. 

Blow up a balloon until it pops.  An animal cell (or a plant cell that's missing a cell wall for some reason) is like this balloon.  Water can flow into the cell until the membranes bursts. 

Now place a balloon into a length of pantyhose and proceed to blow it up.  It will be harder and harder to blow up the balloon because the nylon restricts the balloon.  Virtually impossible to blow it up enough to pop it.  In the same way, the cell wall prevents the cell from reaching its bursting point. 

Newton's 3rd Law: Popping Canisters

 This activity can be done as one activity in a series of stations on Newton's 3rd law, or it could be done as a demonstration if performed on an overhead projector* (does anyone still have those in their classrooms?!?!)

You'll need 2 film canisters (another relic), Alka-Seltzer, water and a pan with a line drawn down the center. 

I took the set-up picture with the transparent canisters, but later switched to the black**

Fill both canisters about half full with water.  You'll want to have the same amount in each canister.  

Cap one of the canisters and lay it on its side so the cap is against the line in the pan. 

For the next portion, you'll need to work quickly....
Add about 1/4 - 1/2 of an Alka-Seltzer tablet to the second canister and cap it.  Then lay that canister so its cap is against the line in the pan. (The two caps should abut one another). 

When the Alka-Seltzer creates enough gas to fill the canister, it will pop the top off.  At the same time it will push the second canister.  Equal force will be applied to each canister, but in opposite directions.  After the explosion, the two canisters will end up in mirrored positions.  

*If you want to do it on an overhead projector, draw a line down the center of a transparency using a permanent marker.  And use a minimal amount of water.  

**This is definitely a demonstration to play around with before you plan to do it in front of your students!  I've done it successfully several times in the past without problems, yet when I went to photograph it, I ran into problem after problem.  The first canisters I grabbed to use leaked so that enough pressure never built up to pop the top off.  Then I used too large a piece of Alka-Seltzer and sent the canister flying out of the pan and off the table (fortunately it didn't go through the brand-new dining room window!).  It's a great little activity, just give yourself a chance to practice it in advance! 

Sound: The Clanging Hanger

This is a simple demonstration that helps make the point that sound needs something to travel through and that air is not a very efficient material for that purpose.

You only need a wire coat hanger and a long length of string.

Tie the string onto the hanger, so that the hanger hangs from the middle of the string.

Swing the hanger from the string so that it bumps into something (a table, chair, wall, etc.) and take note of the sound it makes.  It's kind of a short, clang-y sound.  Nothing very dramatic or melodic about it.

Now, wrap one end of the string around one of your index fingers and the other end around the other index finger.

Place your fingers in your ears (gently, there's no need to jam them in).

Swing the hanger so that bumps into something once again and take note of the sound it makes.  Louder and more like a gong or large bell ringing.

In the first trial, the sound made when the hanger hit the object had to travel through the air to reach your ear drum.  A lot of the sound was lost on the way to your ear.  In the second trial, the sound vibrations travel from the hanger through the string and your fingers to your ear.  Much less sound energy is lost in route and it makes an audible difference.