Projects
Fishing for Ice
Purpose: To observe the effects of salt on ice and hopefully succeed in fishing for ice too!
Materials
-container filled with water
-salt
-string/thread
-ice
Procedures
- Pour ice cubs into the container filled with water.
- Place string across an ice cub that you would like to pick up; it is recommended to get as much surface area touching as possible
- Pour salt over where the string touches the ice, as if you are intending to “tape it” with ice
- Wait for a few seconds, and then lift it up
- If it doesn’t work, don’t worry. You can simply just try again while making sure to wait long enough and put enough salt.
- To lift multiple ice cubes, simply lay the string over all the ice cubes that you would like to pick up, and then repeat the same procedure while pouring salt on all of them
Explanation
When salt is added to ice, the salt dissolves into the thin layer of water on the ice, lowering the melting point. Because the melting point lowers, the ice cube begins to melt, creating more liquid. This water combines with the salt water solution, effectively diluting it and raising the melting point again. The result of this is the resolidification of ice, where the melted water around the string turns back into ice. With this, the string is trapped in the ice, which is why we are able to lift it up and basically “fish” for ice. This experiment actually uses the same logic that is used in pouring salt on an icy sidewalk to melt it, where the salt is able to lower its melting point and cause it to turn into water.
Bottle Rocket
Purpose: To build and launch a rocket powered by water!
Materials
-cardboard
-hammer
-nail (1 inch or longer)
-tape
-electrical tape
-scissors
-cork
-ruler
-bike pump with inflation needle
-plastic water bottle (half-full of water)
Procedures
- Take the cork and trim it down to 3 cm long
- Take electrical tape and wrap it around the cork five times (add one or two more if the cork does not fit snugly into the plastic water bottle)
- Hammer the nail through the cork to create a hole
- Cut the cardboard into triangles that are 15 cm by 5 cm
- Take the construction paper and wrap it around the bottle; tape it on securely
- For the cone, cut a semicircle with about a 7 cm radius
- Cut a line from the flat side that extends a few centimeters into the semicircle
- fold the semicircle into a cone shape, and tape it together
- Tape the cone onto the bottom of the water bottle (the water bottle should be launched while being upside down)
- Attach all four cardboard triangles as fins for the rocket using tape
- Make sure to have the bottom of the fins about 7 cm below the bottom of the upside down water bottle
- To launch, remove the bottle cap from the rocket
- Insert the inflation needle into the hole in the cork
- Push the cork into the opening of the water bottle, making sure that no water leaks out
- Using the bike pump that attaches to the inflation needle, pump air into the rocket and watch it shoot out into the sky!
Explanation
When we put the cork into the opening of the water bottle, we effectively are trapping the air inside of it. Once we start pumping air into the bottle through the inflation needle, the air within the bottle begin to exert more pressure on their surroundings. In other words, by pushing more air into the bottle, the air molecules inside the bottle want to escape, creating pressure on both the plastic water bottle and the cork. After a certain amount of air is pushed inside, the cork bursts out from the bottle because it is the weakest link. This allows the pressure built up from the air to push the water out of the plastic bottle at a high force, which launches the rest of the rocket upwards due to Newton’s Third Law. Newton’s Third Law states that for each action, there is a reaction, and for each force, there is an equal and opposite force. The force of the water going out the bottle downward produces an opposite force that launches the bottle upward into the air. The water bottle does not continue moving upward forever because the force of gravity pulls it back down to the Earth after some time.
Dyeing Flowers
Purpose: To dye flowers different colors while observing the processes of a plant. Disclaimer: We are not trying to kill plants
Materials
-cups filled halfway with water
-celery
-flowers with white petals
-scissors
-food dye (different colors)
-straws (or some other rod that you can use to stir)
Procedures
- Take the flowers and trim them so that only the flower and the stem are left (remove any excess leaves)
- Take the scissors and carefully split the stem of one of the flowers in half
- Add six drops of a specific colored food dye into each bottle of water
- Stir them with the straws
- Place each of the flowers and celery in a cup with a specific color of your choice
- For the flower that was split in half, place one half of the stem into one cup with a color of your choice, and the other half into another cup with a different color
- Leave it for 24-48 hours
Explanation
Plants have an important process named transpiration, in which water flows from the roots to the leaves and then is lost from the leaves through evaporation. In this process, there are tubelike structures called xylem that carry water and nutrients up the plant through the roots. In this experiment, we are using this concept of transpiration in order to change the color of the plant. As can be seen in the celery, there are streaks of color along the plant because the dyed water is being transported up. With the leaves, the color shows up on the petals because that is where the water ultimately goes to after it is transported up the plant.
Lava Lamps
Purpose: To make lava lamps!
Materials
-oil
-clear cups
-water
-oil
-straws (or other stirring rods)
-food coloring
-Alka-Seltzer Tablets
Procedures
- Fill all the cups with a little bit of water (around 1/10th full)
- Add food coloring of your choice to each of your cups
- Stir the mixture with the straw
- Take the oil and pour it into each of the cups (fill it almost up to full)
- For the final step, take an Alka-Seltzer Tablet and place it in each of the cups to activate the lava lamp
Explanation
The reason these lava lamps work is because the alka-seltzer tablets react with water to form carbon dioxide gas. These carbon dioxide gas molecules have much lower density, and they carry the water droplets with food coloring to the top. Once it reaches the top, the carbon dioxide bubbles pop and, since the water is denser than the oil, the colored water sinks back down to the bottom. The reason why this works is because water is denser than oil and they are insoluble in one another. In other words, they do not mix together well at all, and the water will sink below the oil because denser objects sink.
Inflating Balloons
Purpose: To inflate balloons using a chemical reaction!
Materials
-baking soda
-a spoon
-balloons
-empty plastic water bottles
-white vinegar
Procedures
- Pour the white vinegar into the water bottles until it reaches the second line from the bottom (around 1/6 full)
- Add one spoonful of baking soda into each balloon
- Attach each ballon over the mouth of the vinegar filled water bottle without letting any of the baking soda out of the balloon
- To inflate the balloon, lift up the attached ballon to let the baking soda fall into the vinegar and air will start to expand, inflating the balloon.
Explanation
The reason why the balloon seems to inflate on its own is because when baking soda contacts vinegar, the two react to produce carbon dioxide gas. As more and more carbon dioxide gas fill up the bottle, the gas has nowhere else to go so it pushes into the balloon and starts to inflate it. The more carbon dioxide gas that is produced, the more inflated the balloon will become. Furthermore, the warmer the temperature, the more inflated the ballon will become. This is similar in fashion since warmer temperatures will cause the gas particles to move around more and more movement in the particles means more inflation for the balloon.
Extracting Strawberry DNA
Purpose: To extract and observe DNA from strawberries!
Materials
-laminated construction paper (construction paper wrapped with food wrap also works)
-ziploc bag
-strainer
-3 strawberries
-a toothpick
-a spoon
-a clear cup
-isopropyl alcohol (rubbing alcohol)
Procedures
- Start by removing all the green leaves and stem from the strawberry and put them all in the ziploc bag
- Close the ziploc bag tightly and start squeezing/smashing the strawberries (more liquid can result in more visible DNA)
- Strain the smashed strawberries from the ziploc bag into the clear cup making sure to get as much of the liquid as possible
- Pour a nice layer of rubbing alcohol over the top of the strained strawberries and leave it for a few minutes
- At the top of the rubbing alcohol, white strands of DNA will form and use the toothpick to fish the strands out for observation.
Explanation
The DNA can be extracted in this manner because smashing the strawberries is basically breaking the cells and nucleus, allowing the DNA to be revealed. To separate the DNA from the rest of the strawberry and make it more visible, the rubbing alcohol comes in and acts as a precipitate (extracts DNA from the rest of the strawberry). The alcohol takes the revealed DNA from the strawberry solution and puuls it out with the rest of the alcohol, revealing strands of visible DNA.