Why Does the Water Pour Down the String Science Experiment

Can you pour water out of one container and into another? Of course you can! But can you do it when the containers are a foot apart?

In this easy science experiment, we are going to use a little science “magic” to explore cohesion, adhesion, and hydrogen bonding while having fun.

Watch our demonstration video, print out our instruction sheet, and gather your materials to get started. A simple scientific explanation of how the experiment works is included.

JUMP TO SECTION: Instructions | Video Tutorial | How it Works

Supplies Needed

• Empty measuring cup (preferably one with a handle as well as a spout)
• A piece of yarn/string (approximately 2 feet in length)
• Water (enough to fill your measuring cup)
• Empty glass cup

Pouring Water Down String Science Experiment Instructions

Step 1 –Tie one end of the yarn/string to the handle of the measuring cup.

Step 2 – Fill your measuring cup with water. Make sure it is almost filled to the top.

Step 3 (optional) – Add a few drops of food coloring to your water. This isn’t required but does allow you to better observe the experiment and watch the water.

Step 4 – Take the yarn/string and place it into the water. Make sure it is completely submerged and is very wet.

Step 5 – Take the end of the wet yarn/string that isn’t tied to the measuring cup and place it into the empty cup.

Step 6 – Slowly lift the measuring cup into the air, enough to where the yarn/string is tight. (Note: be sure to hold the loose end of the yarn so that the yarn/string is tight.)

Step 7 – Slowly pour the water and watch as the water moves down the string into the empty glass. Do you know the why you were able to pour the water into the glass from a foot away? Find out the answer in the how does this experiment work section below.

Video Tutorial

Use Science “Magic” to Pour Water Down a String

How Does the Science Experiment Work

You are able to pour water down a string because water is both cohesive and adhesive.

• Cohesion – the sticking together of particles of the same substance.
• Adhesion – the action or process of adhering to a surface or object.

Water has a strong cohesive property because of the water particles’ ability to form hydrogen bonds with one another. As a result of this strong cohesive property, water droplets will stick to one another. In addition, water has a strong adhesive property because of water’s tendency to stick to other molecules with a positive or negative charge As a result of this strong adhesive property, water will stick to other things.

During step four of the experiment, the string is submerged in the water. When the string is removed from the water it is wet. This is because the water adheres (or sticks) to the string. This is adhesion.

On step seven of the experiment, the water being poured out of the glass will cling to the water that is attached to the string (this is cohesion) and will move down the string into the empty glass.

A hydrogen bond is a chemical bond between a hydrogen atom (positively charged) and a negatively charged atom (like oxygen). Water molecules like to form chains because the positive end (hydrogen end) of one water molecule is attracted to the negative (oxygen end) of another water molecule.

I hope you enjoyed the experiment. Here are some printable instructions:

Why Does the Water Pour Down the String Science Experiment

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Materials

• Empty measuring cup (preferably one with a handle as well as a spot)
• A piece of yarn / string (approximately 2 feet in length)
• Water (enough to fill your measuring cup
• Empty glass cup

Instructions

1. Tie one end of the yarn / string to the handle of the measuring cup.
2. Fill your measuring cup with water.  Make sure it is almost filled to the top.
3. Add a few drops of food coloring to your water. This isn’t required, but does allow you to better observe the experiment and watch the water.
4. Take the yarn / string and place into the water. Make sure it is completely submerged and is very wet.
5. Take the end of the wet yarn / string that isn’t tied to the measuring cup and place it into the empty cup.
6. Slowly lift the measuring cup into the air, enough to where the yarn / string is tight.  Note:  be sure to hold the loose end of the yarn so that the yarn / string is tight.
7. Slowly pour the water and watch as the water moves down the string into the empty glass.