Bend+Water+with+Electrostatic+Charge

• Three small Styrofoam cups (alternatively, you can use two paper cups to hold the water and an inflated balloon to provide the static charge) • Toothpick • Water • Someone with a head of clean, dry hair
 * Materials **

• Carefully push a toothpick half way through the bottom of one of the Styrofoam cups. Don’t remove the toothpick—leave it stuck in the cup to ensure a gentle trickle of water when you fill it up. • Hold this cup directly over the second Styrofoam cup. • Fill the top Styrofoam cup (with the toothpick in the bottom) with water, and make sure that it is leaking a steady but small stream of water into the cup below.
 * Preparation **

• Observe how the water is flowing straight down from the top cup into the one below. • Rub the third Styrofoam cup against the head of someone with clean dry hair for several seconds to get a static electrical charge (you can tell this happens when the hairs start to stand apart from each other). • Hold this statically charged cup near the stream of water without letting it get wet. • //What happens to the stream of water? // • Now move the cup away from the water stream. What does the water do? • **<span style="color: #323232; font-family: Georgia,serif; font-size: 18px; vertical-align: baseline;">Extra: **<span style="background-color: #ffffff; color: #323232; font-family: Georgia,serif; font-size: 18px;"> Try the activity with other objects, such as a paper cup, a balloon you've rubbed against your hair or other items. //<span style="color: #323232; font-family: Georgia,serif; font-size: 18px; vertical-align: baseline;">What works to change the water's stream? What doesn't? //
 * <span style="color: #323232; font-family: Georgia,serif; font-size: 18px; vertical-align: baseline;">Procedure **

//<span style="color: #323232; font-family: Georgia,serif; font-size: 18px; vertical-align: baseline;">Read on for observations, results and more resources. //

<span style="background-color: #ffffff; color: #323232; font-family: Georgia,serif; font-size: 18px;">What happened to the flow of water when the statically charged cup came close to it? What happened when you took the statically charged cup away? Why do you think this happened?
 * <span style="color: #323232; font-family: Georgia,serif; font-size: 18px; vertical-align: baseline;">Observations and results **

<span style="background-color: #ffffff; color: #323232; font-family: Georgia,serif; font-size: 18px;">When you rubbed the Styrofoam cup in the hair, negative charges (electrons) moved from the hairs to the surface of the cup, giving the cup a negative charge. The water falling out of the top cup is made out of positive and negative pieces that are all jumbled together. But as the negatively charged cup approaches the stream, the positively charged parts of the water molecules (the hydrogen atoms) are attracted to the negative charge and move the whole stream toward the cup.

<span style="background-color: #ffffff; color: #323232; font-family: Georgia,serif; font-size: 18px;">Why doesn't the water get pulled all the way sideways to attach itself to the surface of the cup? Even though the static electric pull between the negative and positive forces is strong, the water is still heavy enough to be pulled down by gravity. So when you take the charged cup away from the stream, gravity takes back over entirely and pulls the water straight down.

<span style="background-color: #ffffff; color: #323232; font-family: Georgia,serif; font-size: 18px;">Pour out the water and carefully remove the toothpick. You can rinse and reuse the Styrofoam cups that don't have a hole in them.
 * <span style="color: #323232; font-family: Georgia,serif; font-size: 18px; vertical-align: baseline;">Cleanup **