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Science Rocks!


Saltwater Tester

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your results

Sent in by:
The ZOOMers

Measuring salt never sounded so good.
Materials

Materials Needed


  • masking tape
  • 9-volt battery
  • buzzer
  • 2 Popsicle™ sticks
  • aluminum foil
  • water
  • saltwater

Instructions

Instructions


  1. Check with a grown-up before you begin.
  2. How can you tell if water is salty? You could taste it - or you could use a saltwater tester!
  3. A saltwater tester uses electricity to tell you if water is salty or not. Here's how to make your own.
  4. First, cover two Popsicle™ sticks with metal - the ZOOMers used aluminum foil.
  5. Then, get a buzzer - you can buy one at an electronics store - and tape the red wire of the buzzer to the positive end of the battery. The positive end will have a plus sign on it.
  6. Next, tape one foil-covered Popsicle™ stick to the black wire of the buzzer. Tape the other one to the negative end of the battery. The negative end will have a minus sign on it.
  7. You can see if your tester is working by touching the metal together. This will complete the circuit and make the buzzer buzz. If it doesn't buzz, check your connections to make sure everything is taped together in the right way.
  8. Now to use your saltwater tester, put just the tips of the metal in saltwater, about an inch apart. Make sure the two metal parts don't touch. The saltwater will act like a wire, connecting the metal sticks, completing the circuit, and making the buzzer buzz.


Here's the sci scoop on how this works. The buzzer buzzes in saltwater because the saltwater acts like an invisible wire to connect the circuit. That's because when you add salt to water, the salt molecules dissolve in the water and break into smaller parts called ions. The ions carry electricity through the water.
Fresh water doesn't have these ions. So it's harder for the electricity to move through the water. It doesn't complete the circuit, and the buzzer doesn't buzz.
What else besides saltwater will conduct electricity and make your buzzer buzz? Try sugar water, vinegar, or whatever else you can think of. Check it out, and be sure to send your results to ZOOM!

Some of your Results

Cheyenna, age 11 of TN wrote:
Pepper- No. Bubble Juice- Yes. Pepsi- Yes. Milk- Yes. Water- No. Saltwater- Yes. Sugar water- No. Vinegar- Yes. Tomato Juice- yes. Baking soda- Yes. Blue Cheese- Yes. Mayonaise- Yes. Mustard- Yes. Ketchup- Yes.

Jackie, age 8 of El Paso, TX wrote:
It was cool. I made saltwater that was amsome. You should try it one day.

Shanyn, age 12 of Magna, UT wrote:
The best buzz I got was from the orange juice, then the salt water, tomato juice and then Magna water.

Yu, age 8 of New York, NY wrote:
The saltwater tester buzzed when I put it in the salt water, it also buzzed when I put it in vinegar, it didn't buzz in fresh water or cold sugar water. It also buzzed in sugar water.

Madelyn, age 4 of Chicago, IL wrote:
Plain water no. Salt water yes. Sugar water no. Oxy Clean water yes.

Jaeden, age 10 of Brush Prairie, WA wrote:
i tried it but I added something to it. I put sugar in the water and baking soda and it was awesome.

Motasem, age 12 of Paterson, NJ wrote:
i used a light bulb instead of a buzzer and it worked.

Carolina, age 12 of Mount Vernon, NY wrote:
it was so easy. i've done it so many times yet it is interesting.

Ekene, age 10 of Baltimore, MD wrote:
I didnt feel any buzz I checked it twice but anyway it was really cool thanks for saving my butt!!!

Maggie, age 12 of Scranton, PA wrote:
when I did I used it for a 6th grade science project. it worked I had to use masking tape. you had to hold the wire on the stick it didnt stay but the expeirement worked I was so happy

Courtney, age 11 of Killen, TX wrote:
this saltwater tester was so cool I shrade it with all of my frineds and they thoght it was so cool too I touck some picers and sod my franeds. the night I staed at my fraends house we were wathing it and we soll it and she saed this project is so cool so I thought that I wouild give you a email and tell all about and how cool it was

Keisha, age 11 of New York wrote:
when I did this experiment I found it very cool now I do this with everything I drin

Amanda, age 12 of Paterson, NJ wrote:
i loved doing that project. it was sooooooo cool. my teacher loved it when she saw it.

Aspen, age 10 of Matamores, PA wrote:
When I did it I other kinds of things such as jelly, dish soap, and apple juice some of them buzzed some didn't. It worked great!

Nami, age 10 of Wallington, NJ wrote:
it worked and it was awsome now I use it to see if my poland spring water has salt!

Tuli, age 9 of Virginia Beach, VA wrote:
I tested it in different liquids, and the buzzer went off. It even went off with bottle water and my tap water??? I didn't understand why? I am going to change the foil and do it again... wish me luck.

Emilio, age 11 of Medford, OR wrote:
it worked salt water made it buzz fresh water didnt that was cool thanks!

Mariam, age 10 of Carteret, NJ wrote:
I used a 6volt battery and buzzer along with other liquids such as vinegar, saltwater, oil and water. They all worked except for the oil!

Jonathan, age 13 of Greenleaf, WI wrote:
When I put salt in the water, the buzzer was extremely loud. I tried putting sugar in the water, but it didn't work. I think I know why. Sugar is a deionizer, and electricity travels through the ions in the water. If the sugar gets rid of the ions, electricity cannot travel through the water.

Bailey, age 12 of N. Battleford, SK wrote:
This was a cool experiment. Me and my friend tried some other liquides like pop and we even tried making the buzzer buzz threw a solid. Me and my friend did this for a science fair this year. I loved it.

Lena, age 9 of Cleveland, OH wrote:
We were struggling putting it together, but when we got it to work we were so excited! I am doing this for my 3rd grade science fair.

Emarah, age 9 of New York, NY wrote:
It made a noise in the water and nothing in the saltwater.

Angelica & Hiram of El Paso, TX wrote:
At first it didn't work, but then we saw that the red wire and the black wire were in the wrong places, so we switched them, and then it worked perfectly.

Mathangi, age 10 of Plainsboro, NJ wrote:
It worked perfectly. I did it in my third great Science Fair two years ago. Everybody was amazed.

Kristen, age 12 of Brooklyn, NY wrote:
When I submerged the popsicle sticks in the tap water with added salt, I could believe my ears, it buzed. When I submerged the popsicle sticks in the tap water with no added salt it was still and no sound was heard. I did this as a science fair project! AWESOME and COOL prject

Katie, age 8 of Mendon, IL wrote:
The buzzer buzzed in saltwater and sugar water. This is for my 2nd grade science fair. I am so excited it worked.

Izabella, age 10 of Los Angeles, CA wrote:
when I put it in the saltwater it buzzed. when I put it in the regular water it made a ringing noise.

Joost & Bart, age 13 wrote:
sea water gives a reaction, water with added salt gives a reaction, pool water gives no reaction, minaral water gives no reaction, tap water gives no reaction


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