Homemade Ice Cream!

In class recently, we have made homemade ice cream. A lot of people said that their ice cream tasted salty, but my partner Caroline and I had completely sweet ice cream. We decided to make chocolate ice cream.

It included:

• milk


• sugar


• vanilla extract


• chocolate syrup


• ice (to cool)


• salt (also to cool)

We mixed all of the ingredients together and mixed it all together. At first the ice cream was a liquid. We put a bag full of the mixture into a larger bag and filled it with ice and salt to freeze the ice cream. Salt makes the ice colder, and that allowed us to complete the lab in a shorter amount of time. When the ice cream froze more, it turned more into a solid form, but still half liquid because we didn't wait long enough for it to freeze more. The science in this experiment is to show that the colder the temperature, the more solid the substance.

Floating Popsicle Raft!

Photocredit: Jensen Li

For my other mini project, Jensen Li and I decided to create a mini raft using old popsicle sticks, tape, and Elmer's glue. We glued each popsicle stick facing flat onto another one into a square shape. The raft was built about 14 sticks high. For the bottom of the raft, we taped a row of about ten popsicle sticks together with no gaps, all facing flat. Then we glued them to the walls of the raft. Before we put the raft in the water for our test, we covered the bottom in a gray masking tape to be sure that the water would not seep through the sticks. When we placed it in the water, it floated. It was a success! After a few seconds of completely floating, the raft began to slowly submerge a few centimeters. This allowed the water to go through the gaps in the walls of the raft. The raft sank approximately 1 inch and then stayed at that level for several minutes until we determined that the test was over. In order to make a more efficient raft, we could have made sure that there were no gaps in the walls or bottom of it and we could have used a lighter, less dense type of material so it would float with more ease, as well let the glue dry so it would have had a more stable structure.

Scientific Facts:

• The density of the sticks are low enough to float as opposed to a rock or more dense object
• The tape is air tight sealed and can keep the water from leaking through
• The wet glue caused a mis-shaped structure and water to leak through the raft
  

More Information:

How to Make a Tin Foil Raft

Chemistry Standard: Radioactive Isotopes

Chemistry Standard (Nuclear Processes) 11c: Students know some naturally occurring isotopes of elements are radioactive, as are isotopes formed in nuclear reactions.

There are several natural radioactive isotopes as well as synthetic radioactive isotopes that are formed in nuclear reactions. These are also called "radioisotopes." A radioactive isotope means that the isotope has an unstable nucleus. The isotopes split up or decay and give off radioation. Almost every chemical element has at least one or more radioactive isotopes. All elements with an atomic number greater than 83 are radioisotopes; elements with an atomic number of less than 83 have at least one radioactive isotope. A popular element, hydrogen, has three isotopes- but only hydrogen-3 is radioactive and the other two are stable. There are more than 1,000 known radioactive isotopes and approximately 50 of them are found in nature. The rest occur from nuclear reactions or are descendants of radioactive products.

Here is a list of commonly known elements and their radioactive isotopes:

• Hydrogen-3
  
• Carbon-14
  
• Calcium-41
  
• Iron-59
  
• Nickel-59
  
• Cobalt-60
  
• Zinc-65
  
• Silver-110
  
• Tin-126
  
• Iodine-129
  
• Iodine-131
  
• Iodine-134
  
• Lead-210
  

Although this is unknown to many people, radioactive isotopes have several common uses.

Used in:

1. Smoke detectors (Americium-241)


2. Food Irradiation
   
3. Agricultural farming as radioactive tracers


4. Medical uses


5. Archeological dating
6. Irradiation in pest control

Click here to watch radioisotope video.

Unbreakable Water Balloon!

PhotoCredit: Lexi C.


For my mini project I tried to create an unbreakable water balloon. My partner, Caroline Murray, and I used tape, post- its, and a green balloon. We filled the balloon with water and covered it with post- its. Then we wrapped 2 inch thick tape around the balloon over every inch with several layers. We thought that when we dropped it, all of the tape would hold the water inside and it would be a sealed object. When we went outside to test our experiment, we threw the balloon about 5 ft away, so we wouldn't get wet, and learned that it did not work. Obviously the water leaked out of the tape because it was not air tight. The pressure allowed the balloon to burst and the water to flow out, seeping through the leaks in the tape spaces.

Things we would have done differently:

• Use suran wrap along with larger more efficient tape
• Make the balloon smaller so it will be less chance it will pop
• Drop it from a lower distance
• Put air in the balloon as well

ISupposeWe Clean Pennies

This experiment is to clean old, dirty pennies using resources near you.

Materials needed: old pennies, 1/4 cup of white vinegar, 1 tsp salt, nonmetal bowl, and paper towels

Procedure:

1. Pour the vinegar into the bowl and add salt

2. Put about five pennies into the bowl and count to ten slowly
3. Take the pennies out and wipe them with the paper towel

4. You will have shiny pennies!

Safety Precautions:

• Don't use collectible coins, you will lower their value
• Wear safety goggles so you don't get any vinegar in your eyes
• Do not mix pennies with any other coins or they will become discolored
• Do not use scratched pennies or pennies older than 1982, they may become hollowed out due to the fact that vinegar dissolves zinc

Scientific Principles:

1. Vinegar acid reacts with salt to remove copper oxide

2. If you don't dry the pennies, the acid will create malachite on them.

If you are interested in different ways to clean your pennies, there are several solutions:

• Vinegar and baking soda
• Vinegar and lemon juice
• Video example

Gas Laws

We can calculate many different things using different formulas. We can even measure our atmosphere's local air pressure. The formula's we use to deal with gases are the following:

Boyle's law (above)- P1V1=P2V2 (constant temperature)
Charle's law- V1/T1=V2/T2 (constant pressure)
Gay-Lussac's law- P1/T1=P2/T2 (constant volume)
Combined gas law- P1V1/T1=P2V2/T2 (sample of gas)
Avogadro's law- V/n= k (two gasses at constant T and P)
Ideal gas law- PV=nRT (n= number of moles of gas particles, R= the ideal gas law constant)

Atmosphere

The atmosphere has many different ways of being measured. Pressure of the atmosphere can be measured in the following ways that are all equivalent:

- 1 atm
-760 mm Hg
- 760 Torr
-101.325 kPa
-14.7 lbs/square inches
-29.92 in Hg

All of these terms can be converted into one another.