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

   3 electrons
2. 2.

   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
3. 3.

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

   • Nothing until they touch
   • They push apart
   • They pull together
4. 4.

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

   • Push apart and stand out
   • Stick together, since both are +
   • Pull together into a clump
5. 5.

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

   • Protons
   • Electrons
   • New charges made by rubbing
6. 6.

   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
7. 7.

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

   • It lost some electrons
   • It gained electrons
   • It gained protons
8. 8.

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

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

9. Read this first

   Use this

   Charge diagram.

10. 9.

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

    • Positive, since it has + marks
    • Negative, since it has − marks
    • Neutral: the marks cancel
11. 10.

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

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