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

Mixtures: Home Mixture Separation

Mix up some salt, poppy seeds, iron filings and sand, in about equal proportions. 

Give each student a small sample of the mixture and challenge them to take the mixture home and separate the components. 

The students need to return the separated components, as well as a description of the steps they followed in the separation. 

The original version of this lab requires a parent signature for credit.  It also has students rate how successful they were in separating and recovering each component (on a scale of 1-10) and asks them what they might do differently if given the same problem to solve.

It's a nice way to remind students that science does not have to occur in the lab and it does not necessarily require fancy equipment.  It's also a chance to involve parents and for students to actually show their parents what they've been learning in class. 

If you have students for whom it may truly be a problem to complete the activity at home, I would allow them to schedule a time to work on the activity in the classroom. 

One story.... I once had a student who claimed to have dissolved the salt in water and later boiled off the water to leave the salt.  The only problem was, the salt sample he handed in looked like salt straight from the shaker.  When you reclaim the salt through this procedure, it doesn't look like salt that comes straight from the canister, instead it's kind of flaky and a little powdery.  Busted!

Atoms/Periodic Table: Bingo

Have students fill in a blank bingo card with any numbers between 1 and 50.

You can make up your own clues involving elements' atomic numbers, protons, electrons, and neutrons, or you can use mine:

1 - # of protons in Hydrogen
2 - # of neutrons in Helium
3 - # of electrons in Lithium
4 - # of neutrons in Lithium
5 - # of protons in Boron
6 - atomic number of carbon
7 - # of neutrons in Nitrogen
8 - # of electrons in Oxygen
9 - atomic mass of Beryllium
10 - # of protons in Neon
11 - atomic number of sodium
12 - atomic mass of Magnesium
13 - # of in Aluminum
14 - # of protons + # of neutrons in Nitrogen
15 - # of protons in Phosphorous
16 - # of protons in Sulfur
17 - # of electrons in Chlorine
18 - # of neutrons in Chlorine
19 - # of protons + # of neutrons in Fluorine
20 - # of neutrons in Potassium
21 - atomic number of Scandium
22 - # of protons in Titanium
23 - # of protons + # of neutrons in Sodium
24 - atomic mass of Magnesium
25 - # of electrons in Manganese
26 - # of neutrons in Titanium
27 - atomic number of Cobalt
28 - # of protons + # of neutrons in Silicon
29 - # of protons in Copper
30 - # of protons in Zinc
31 - # of electrons in Gallium
32 - atomic number of Germanium
33 - atomic number of Arsenic
34 - # of protons in Selenium
35 - # of neutrons in Zinc
36 - # of electrons in Krypton
37 - atomic number of Rubidium
38 - atomic number of Strontium
39 - # of protons in Yttrium
40 - atomic mass of Argon
41 - # of electrons in Niobium
42 - # of neutrons in Arsenic
43 - atomic number of Technetium
44 - # of protons in Ruthenium
45 - atomic mass of Scandium
46 - # of  electrons in Palladium
47 - # of electrons in Silver
48 - # of protons + # of neutrons in Titanium
49 - atomic number of Indium
50 - # of protons in Tin
I recommend making up a list ahead of time, to make sure you don't use the same number over and over while completely skipping others.

I wrote my clues on index cards.  Then, for each round I shuffle the deck and draw the cards from the top.

Chromatography: Which is Which?

 Pictured above are 2 M&Ms and 2 Reese's Pieces.  Can you tell which are which?

Do you think the brown dye used to coat them is identical?  It certainly looks like it, but you can use science to determine the difference. 

We'll be using chromatography again, separating the dyes found in each candy coating. 

To begin, cut your filter paper/coffee filter into two strips, about an inch wide.  Label one with an M (for M&Ms) and the other with an R (for Reese's Pieces).

Dip part of a brown M&M into water.  Use the wet portion to draw a line on the appropriate filter paper, about an inch from the bottom.  You'll want to go over the line several times, to make it as dark as possible.

Repeat the above steps with a brown Reese's Pieces and the other piece of filter paper. 

Set up your filter papers so the very end is in water (make sure the line is above the water level).  I used pencils to suspend my filter papers in tall drinking glasses.

Wait and watch.  After sufficient time has passed for the water to move a few inches up the paper (could be as long as half an hour depending upon the paper you use), remove the papers from the water and lay them flat to dry. 

Place the filter paper on a sheet of white paper for the best viewing and observe the differences between the two candies:

The colors are so faint, it is difficult to capture them in a photograph. 



Reese's Pieces



M&M



The Reese's Pieces is largely red with a faint blue line. 

The M&M shows a lot of orange, a little red, and a very faint line of green.

Total Cereal: Iron Fortified

This activity can be used for several different curriculum areas: elements, magnetism and nutrition

Back in the day, Total cereal used to run a series of commercials in which a person had to eat a large number of bowls of their favorite cereal in order to get the same amount of vitamins and minerals they could get in one bowl of Total.  One of those nutrients is iron.  Check out how they fortify their cereal....

Pour some cereal into a cup or bowl.  Pour some water on the cereal and let it sit for 15-20 minutes; enough for it to get nice and soggy and too gross to eat.

Place a magnet (use the strongest magnet you can get your hands on - a regular magnet works, but the stronger the magnet, the better the results) in a plastic baggie*.  Then, use the magnet to stir up the cereal sludge.

When you pull out the magnet, you will find that you have small pieces of iron sticking to the magnet!  The cereal is fortified with iron filings!  Perhaps not the most usable form of iron for your body, but iron none-the-less.

*Putting the magnet in a plastic baggie serves 2 purposes:
 1 - It makes clean-up a LOT easier!
 2 - It can be hard to see the iron pieces on the magnet, but if you pull the baggie off and place it on a piece of white paper, the iron will be easy to spot!

Chromatography: Spinach

Is spinach colored by purely chlorophyll (green pigment)? Or are there other pigments hiding in there, masked by the presence of chlorophyll?

Before beginning, if you aren't familiar with chromatography, you may want to review the basics, here.  

Use a quarter to rub spinach into a piece of filter paper, a couple of centimeters from the end of the paper. (If you’re doing this at home and don’t have lab grade filter paper, have no worries! A coffee filter works beautifully (that’s actually what I used with my students – why spend the money on expensive filter paper!) and even paper towels can be made to work).

 Put about a centimeter or so of rubbing alcohol in a cup.  Place the filter paper in the cup, so the end is in the alcohol, but the spinach transfer is above the liquid.  Allow it to sit.

Now, here's where it would be nice to have a picture of the finished chromatograph.  But, milk spilled on mine before I snapped a picture and I haven't had the opportunity (or spinach) to recreate it.  It's subtle, but you can find both green and yellow pigments on the paper, if you look carefully. 

******
Presented at the 2003 New Jersey Science Convention.

Chromatography: Pinwheel T-Shirt

Sharpie markers may not be soluble in water, but they are soluble in rubbing alcohol.  Use this property to your benefit to create some wearable art (and science)!

Place a dish pan or plastic shoe box inside a plain white shirt.  Pull the shirt taut and rubberband it in place.

Use the markers to make a ring of dots where you want the pinwheel to appear.

Using a dropper, drop rubbing alcohol into the middle of the ring. 

The alcohol will move outward, through capillary action, and carry the ink with it.

If the ink is made of a mixture of colors, you will see the colors separate.  If it's made from a pure color, you will simply see the color radiate outward.

Move the shirt on the box and make another pinwheel. 

Get creative...
...try making your ring of dots with a variety of colors
...what happens if you make your dots in a shape other than a circle?
...what if you start with one central dot?

Chromatography: The Basics

Did you know the black ink is usually made of a mixture of several different colored inks?  You can use a process called chromatography to separate the mixture. 

Here's the basics...

Cut a piece of filter paper (or a piece of coffee filter, or a piece of paper towel) about an inch wide.

Place a dot of ink about an inch from the bottom.

Place a small amount of water (less than an inch) in a cup.  Place the filter paper into the water, so that the paper below the dot is the only part in the water.

The water will travel up the filter paper.  As it travels, it will carry some of the ink with it.  The ink that is made of larger molecules will not travel very far.  The smaller molecules will travel farther up the paper, resulting in separation. 

Now, here's how I use it in my classroom...
I usually make a sign with a silly threat on it.  Something along the lines of, "8th graders small funny."  Mature, right?  It's enough to get the students attention and I tell them that we're going to figure out who wrote it.

I then go through a story.  Something like... "Mr. Krup always has a black Sharpie.  And I saw Dr. Smith with a black Crayola marker yesterday.  Etc."  I use names of teachers in the school - people who are my friends and are good sports.

The students each get a piece of the threat that contains some ink, so they can use it for chromatography. 

Then, they take a wider strip of filter paper and make a mark with each of the 'suspect' markers.

Then they complete the same process as above with this paper, placing the end in water and letting the water wick up the paper. 

At the end, you compare the chromatography results of the evidence and your four suspect markers.  One of the four markers will match the evidence and you'll have your culprit.

Chemistry: What’s a Molecule?

Hold up a piece of paper.

Rip it. Is it still paper?

Rip it. Is it still paper?

Repeat, over and over.

Is there any time it won’t still be paper? Just before that point, you’ve reached a molecule.

Rate of Solution: Sugar Cubes

I did this with 4th grade students who were learning about solutions. It's simple, but they have a good time and learn a little something in the process!

For each pair of students, you'll need:
-Cup/Beaker
-4 Sugar Cubes
-Spoon
-Stopwatch

For the whole class:
-Hot Water
-Room Temperature Water
-A means of crushing sugar cubes

Provide each pair of students with a cup (clear is better - it's hard to see a white sugar cube in a white cup) of room temperature water.

Have them drop a whole sugar cube into the water and time how long it takes for the cube to dissolve (no stirring).

This is their baseline measurement. They'll now test several variables, one at a time.

With a fresh cup of room temperature water, drop in a whole sugar cube and time how long it takes for it to dissolve when you STIR it.

With another fresh cup of room temperature water, drop in a CRUSHED sugar cube and time how long it takes to dissolve (no stirring).

Get a cup of HOT WATER, drop in a whole sugar cube and time how long it takes to dissolve (no stirring).


There are several ways to conclude this experiment. Try one or more...
1 - Have students create bar graphs of the data:
-Room Temperature water vs. hot water
-Stirring vs. not
-Crushed cube vs. whole cube

2 - After students have analyzed their data, have them race to see who can dissolve their sugar cube the fastest. They've got three choices to make: hot or room temperature water, will they stir or not, and will they use a crushed cube or a whole cube.

3 - Along the same lines as #2, have a contest where students try to prevent a sugar cube from dissolving for as long as possible.

Mixtures: The Mistake

This is a fun, open-ended lab for your students to put into practice that which they've learned about separating mixtures. Read the following story to your students (this is the original, you'll want to swap out "Home Ec" for whatever's appropriate in your school). Then, provide them with a sample of the salt and pepper mixture, a variety of tools, and let them have at it.

You may want to read the story to them the day before they'll perform the separation... gives them time to come up with a plan and gives you the opportunity to gather any materials they may wish to use that you hadn't thought to put out.


The Mistake
What kind of day was it? A day like all days - only THE SUBSTITUTE was there. The place was Home Economics and the substitute - one Mrs. Dimwitty. In her demonstration, Mrs. Dimwitty was to add salt and pepper to her baked dish. In trying to save time, Mrs. Dimwitty mixed the salt and pepper together before class. Upon reading teh recipe very closely, she discovered that the salt and pepper had to be added at different times. What an embarassment. What would she do now? All teh salt and pepper she had was in one jar - all mixed up. One of Mrs. Dimwitty's students said she could help if allowed to go to the science department. A short time later she came back with two jars - one containing salt, the other containing pepper. What a relief. The casserole would be a success.

In this lab you are to separate the salt and pepper mixture that you find in your test tube into two piles. Salt must be piled on one paper towel - pepper on another. You WILL NOT get another test tube so be careful. Don't throw anything down the drain until the end of the period. After you have separated the salt and pepper, bring them to the front desk for inspection. There should be no salt in the pepper and no pepper in the salt. After your separation has been approved, give a step by step description of what you did on the back of this sheet.