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

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

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

   After a balloon rubs Luz's hair, each strand of hair is positive. What do the strands do?

   • Stick together, since both are +
   • Pull together into a clump
   • Push apart and stand out
7. 7.

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

   • Electrons
   • Protons
   • New charges made by rubbing
8. 8.

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

   • From the balloon onto the hair
   • Nowhere; rubbing made new ones
   • From the hair onto the balloon
9. 9.

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

   • It gained protons
   • It lost some electrons
   • It gained electrons
10. 10.

    Charge diagram. In the charge diagram, what is the paper bit's charge, Tala?

    • Negative, since it has − marks
    • Neutral: the marks cancel
    • Positive, since it has + marks