Static Electricity

Every week at the end of girls science club, each girl “tells us what she has learned” and gets to pick a small token to take with her. We used to give out candy, but have switched to stickers and balloons (to be healthier!). Balloons are the current hot item, so I thought incorporating balloons into the actual activity would be fun! To incorporate balloons, I themed the activity around static electricity.

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The hour was divided into four activities:

  1. Stick a balloon to the wall. In this activity, we had the girls rub the balloons either on their heads or with wool socks/sweaters, and then stick them to the wall. It was also neat to see the balloons stick to the wool socks! IMG_7885.jpg
  2. Then, we tested out which materials can generate static. We rubbed different types of spoons (wood, plastic, metal) with the wool and tried to “pick up” salt and pepper. One girl spilled her salt on the table and used the balloon to pick it up! I thought that was a great idea!IMG_7890
  3. After determining that plastic was the best spoon material to generate static, we rolled aluminum cans with the balloons. To do this, you rub the balloon and put it near (but not touching) the can.
  4. Lastly, we made butterflies with tissue paper wings. To get the wings to “flap”, we rubbed the ballon and put the ballon near the tissue paper wings.

Thankfully, it was a cold day in Boston and the heat was on high, allowing us to generate a lot of static!

 

 

 

 

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Lava Lamps

In this weeks meeting, we made our own lava lamps. This is an awesome activity because it visually demonstrates the concepts of density, solubility, and chemical reactions. I strongly recommend this activity!

To start, we gave out an assortment of objects including: rocks, styrofoam, different types of sports balls, wood, and coins. Then, we predicted which items would float in water and tested our hypotheses. After some discussion, it was concluded that, “things that are lighter than water float in water”, which is exactly right! Here, we introduced the word density.

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Testing out objects: Does it float or sink?

Next, we passed out the water bottles and filled them with 1/3 water and 2/3 oil using a funnel. This step demonstrated that oil floats on top of water because oil is less dense than water.

Then, we added food coloring. We explained to some of the older girls the word “solubility” and how the food coloring can be dissolved in water, but not oil.

Finally, we added the most exciting ingredient… Alka-seltzer! The chemical reaction between Alka-seltzer and water creates CO2 gas, which allows the water to bubble up through the oil. This creates the “lava lamp” look! If you leave the cap screwed on the bottle, the bottle pressurizes. Although a few girls did this by accident, it demonstrated that the chemical reaction was creating a gas.

For extra flair, we added glitter to our lava lamps. At the end, we also gave out the extra Alka-seltzer tablets, which led to many overflowing bottles! Whoops!

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Here is the activity sheet we used: Lava_Lamp_Activity_Sheet

Cleaning Pennies!

Last week, we had the first meeting of the semester! After a month off, it was great to get started with Girl’s Science Club again. And what better way than with some chemical reactions! 

First, Jane led a discussion on chemical reactions. One of the girls said, “a chemical reaction is when you mix two things and there is an explosion!”, which I think is great description of chemical reactions based on our previous meetings. We have done a lot of exploding reactions, so this activity was a nice way to introduce a new reaction that cleans rather than explodes.

For this activity, we had the girls make and label three different solutions: (1) water, (2) water + soap, and (3) vinegar + salt.

Then, we each made a hypothesis which solution would clean the dull pennies the best. On my side of the table, the popular choice was water! We put old, discolored pennies in each solution, stirred, and waited. After about 10 minutes, we examined the pennies and found that the vinegar and salt solution cleaned the pennies the best, making them look new! We explained that this was because the vinegar and salt were reacting with the “dirt” (aka copper oxide) on the pennies.

Then, after removing the pennies from the cup, we gave each girl a new nut to put in the already used vinegar and salt solution. After a few minutes, the nut became dull and looked like the old pennies! This was unexpected and exciting!

Overall, the hour was filled with experimentation. Many girls tried solutions we hadn’t suggested, including salt water, salty vinegar, soapy vinegar, etc. They were engaged and curious, which was an amazing way to start the semester!

Air Pressure


This week, Jane ran a very succesful new activity about air pressure. To start the activity, Jane lead a discussion about air and did a demonstration using a notecard to seal an inverted cup of water. This demonstration really surprised the girls and lead to an interesting discussion about how air molecules are pushing on the bottom of the notecard (although there are other forces involved, we kept it elementary school level).

After the demonstration, the girls split into two stations to learn about air pressure:

  1. Build a Hovercraft
  2. Balloon Race

At the hovercraft station, the girls constructed their own hovercrafts using a balloon, a CD, a bottle cap (with a small hole already through the top), and a glue gun. One at a time, the girls used the glue gun to connect the cap to the center of the CD. This was actually really fun because many of the girls had never used a glue gun, so as some side science, we learned how the glue gun works and how to use it safely. Then, we blew up the balloons, twisted the balloon so no air leaked, and connected the balloon to the bottle cap. When the balloon untwists, this creates a hovercraft that feels very similar to a hockey puck on an air hockey table. Then, we placed pennies on the hovercrafts too measure the strength of the air pressure. 

At the balloon race station, the girls blew up balloons and attached them to the “racing track”, which was a cylinder paper around a string. When the full balloon was released, the balloon flew along the string, demonstrating how the air leaving the balloon generates enough force to move the balloon along the track. This was really fun, and lead to some exciting balloon races! We also tried the races with different shaped balloons, which were a big hit.

Overall, this was an awesome activity!

EGGcellent Fun

This week we had an egg-cellent time learning about the properties of eggs! We had the girls rotate between three stations:

  1. Determine if an egg is hard boiled without cracking it. At this station, Radost taught the girls that if they spin or roll the egg, the raw egg wobbles more because it has a yolk bouncing around inside! I thought this was very clever.
  2. Learn how to make an egg float in water. I helped run this station and had a blast teaching the girls how to make an egg float. First, we hypothesized whether the egg would sink or float in tap water. Answers were about split: half thought it would sink and half thought it would float. I love having the girls hypothesize what is going to happen before these types of activities. It gives them an opportunity to use their previous knowledge and intuition AND makes the activities more suspenseful! After watching the egg sink in water, we passed around a container of salt and each girl added some salt. I let them know that, with enough salt the egg will float– and it did! We had to add a lot of salt though! This led to a nice discussion about density.
  3. Test the strength of an egg shell. At this station, the girls had to crack 2 eggs, clean them, and balance books on the four half-egg shells. The girls were very impressed at how strong an egg shell is, considering we are so used to cracking them. This was definitely the messiest of stations!

    I think its wonderful to “do science” with a common item, like an egg. What a great activity!

Kaleidoscopes!

For this activity, we used our recent knowledge of light and optics to make kaleidoscopes. The kaleidoscopes turned out awesome! First, we reviewed some facts about light we learned two weeks ago:

  1. White light is a mixture of many colors.
  2. Light travels in a straight line.
  3. Light can pass through an object, be blocked by an object, or be reflected off an object.

For this activity, we focused on #2 & #3 and the word “reflection“. As a warm-up activity, we challenged the girls to bounce a beam of light off of three mirrors. This took some precision and help from the mentors, but eventually was a success!

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After bouncing light of of multiple mirrors, we began the construction of our kaleidoscopes. This involved designing a pattern to look at through the scope, as well as building the triangular mirror structure (made out of mylar) to put inside the tube.

Once the kaleidoscopes were complete, the girls had a blast looking through their kaleidoscopes. They even took pictures and videos through the kaleidoscope, which was awesome!

For more info on how to make the kaleidoscope, check out the activity worksheet: GSC_Kaleidoscope

Creepy Density

Because it was the week before Halloween, we planned an activity that explored density, but put with a creepy Halloween twist! We started by talking about what density is, and showed the girls pictures of a box with lots of colored dots and a box with few colored dots. They quickly realized that the box with fewer dots represented a lower density. Then, we explained that a lower density liquid would float on liquid with higher density.

Next, it was time to start the activity! We started by pouring the highest density liquid (honey) into the bottom of the cups. We then proceeded to pour the other liquids into each girls’ cup in order of density. We added maple syrup, water (colored with food coloring), and vegetable oil.

We handed out paper clips, small legos, and candy corn (which they were extremely excited about) for the girls to drop into their layered liquids and see which level they floated on. We talked about how you can compare the density of the solids objects to the density of the liquids by seeing where they stayed in the cup. The cups ended up looking really cool, with the separated layers of different colors, and the girls seemed to get really into it!