#2 Penny Science

And you thought that a penny was a penny.

Materials:
1. 2 film canisters, any type. Save the lids, so you can store the pennies in the canisters for next time.
2. One film canister from Advantix film. (oval)
3. 40 pennies before 1982.
4. 40 pennies after 1982.
5. A ruler.
6. Masking tape

Directions:
1. Use a small loop of masking tape to tape each of the round canisters to each end of the ruler.
2. Balance the ruler with the canisters, on the Oval canister.
3. Place a known amount ( start with 10 as a minimum) of the after 1982 pennies in one canister. Predict how many of the before 1982 pennies it will take to rebalance the ruler. (Construct a Data Table to keep track of your results). Repeat using pennies in increments of 10.

Data Table:

After 1982     Prediction for      Experiment for
                before 1982         before 1982 
________________________________________________________
10
________________________________________________________
20
________________________________________________________
30
________________________________________________________
40
________________________________________________________

Why?
You should discover that there are about 9 before 1982 pennies for every 10 after 1982 pennies. This is because in 1982 ( why we are always using pennies before or after but not in 1982) the Treasury Department stopped making pennies from Copper and switched to Zinc that is Copper clad. The Copper has a Density of 8.9 g/ cc and the Zinc a Density of 7.0 g/ cc . So the Copper pennies have more mass ( try using equal numbers of each on either side and you will find the Copper pennies have more mass). Copper pennies have a mass of 3.090g and Zinc pennies have a mass of 2.505 grams ( these are based on a very large sample and averaged).

Scientific Concepts:
We are demonstrating the concept of Mass ( Inertia, or the amount of Matter), Chemical Elements ( Copper and Zinc are 2 different elements with different Physical properties). Density, the mass divided by the volume will give the density.
The principle of First Class levers is demonstrated by the balance.

More you can do;
Have students find the actual mass, volume and density of the different pennies.
Demonstrate what happens when a penny from each group is heated ( Care should be taken, the newer pennies will melt, do not let allow children to heat the pennies).
Research other properties of Copper and Zinc that could be useful.

 

#16 Smell, or Where are you Mommy?

Many animals locate and recognize their young by "smell", thank goodness we do not!

Materials:
1. Sets of black film canisters (5 or 6 per set), all identical, enough sets
for each animal you want to create. You also need different color caps, black and gray are easy to obtain for the black film canisters.
2. A bottle of concentrate ( peppermint, licorice, etc.) for each animal.
3. Enough cotton balls so you can place one in each canister.
Directions:
1. The more sets the more fun. I recommend at least 6 sets of 5 each, but you
can vary this with the size of the group.
2. First, mark a simple code on the bottom of each canister to help you sort them when you are finished, unless you like smelling all of those smells!
I usually make an x, or use Roman numerals.
3. Place each set together, and add a cotton ball to each canister. Add a few
drops of the concentrate e.g. peppermint to all of the canisters in a set. Place a Black cap on one canister ( the mom or dad) and gray caps on the others ( the kids). Continue for the other sets.
4. Separate the canisters for the Moms and Dads (black caps) and mix all of the
other canisters up.
5. Give one Mom / Dad canister to a child until they are all gone, Assign each Mom/Dad a location in the room to be "Home".
6. Pass out t he rest of the canisters randomly, to the rest of the children.
7. Now, the Moms/Dads must find their children by smelling their canisters and matching it to the children's canisters, of course the children should also smell Moms/Dads to make sure that it is correct. When a Mom/Dad finds a child ( and the child agrees), they will be sent to their home.
8. When all children have been sent home, the moms/Dads go home also.
9. Check to make sure that all children belong to the parents and vice versa, Do
not be surprised to find the wrong children at a home or children that were never chosen!
Why?
Our sense of smell is not all that great, and when we have to use it to make decisions, especially when there are other smells interfering, we make mistakes.
Scientific Concepts:
In the animal Kingdom, it is common for animals to locate their young by smell alone. Most wild animals have a sense of smell that is thousands if not millions of times more sensitive than ours.

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