Static electricity: like charges push, unlike charges pull

Answer Key - Grade 8 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   After rubbing, Ari's balloon shows 3 + marks and 5 − marks. Each mark is one charge. How many extra electrons does it have?

   2 electrons
2. 2.

   After rubbing, Bo's balloon shows 4 + marks and 7 − marks. Each mark is one charge. How many extra electrons does it have?

   3 electrons
3. 3.

   After rubbing, Esme's balloon shows 2 + marks and 6 − marks. Each mark is one charge. How many extra electrons does it have?

   4 electrons
4. 4.

   Jun rubs two balloons on hair, and both become negative. What do they do when held near each other?

   • They push apart
   • Nothing until they touch
   • They pull together
5. 5.

   A rubbed balloon is negative, and the hair it rubbed is positive. What happens when Kira holds the balloon near the hair?

   • The hair is pushed away
   • Nothing; hair has no charge
   • The hair is pulled toward it
6. 6.

   When Milo rubs a balloon on hair, which particles move from one to the other?

   • Electrons
   • Protons
   • New charges made by rubbing
7. 7.

   Rubbing leaves Noah's balloon negative. Which way did the electrons go?

   • Nowhere; rubbing made new ones
   • From the hair onto the balloon
   • From the balloon onto the hair
8. 8.

   After rubbing a balloon, why is Pia's hair positive?

   • It gained protons
   • It gained electrons
   • It lost some electrons
9. 9.

   In the charge diagram, which object is negative, Ren?

   • The hair, since it has 5 + marks
   • The balloon: more − than +
   • Both, since each has − marks
10. 10.

    Charge diagram. In the charge diagram, what will balloon A and balloon B do near each other, Zee?

    • Nothing, since both are negative
    • Push apart
    • Pull together