1. Complete Activity 4.1 (Page 38).
A. Comb dry hair. Does the comb then attract small pieces of paper?
B. Rub a glass rod with a silk cloth and bring the rod near an inflated balloon. Observe what happens.
Answer:
Aim: To observe if the comb attracts paper and what happens if the rubbed silk cloth is brought near the inflated balloon and make conclusions based on that.
Materials Required: Comb, small pieces of paper, glass rod, silk cloth, inflated balloon.
Procedure:
(i) Comb your hair while dry and bring the comb near the small pieces of paper.
(ii) Now rub the glass rod with the silk cloth and bring the rod near the inflated balloon.
Observations:
- The comb will attract the small pieces of paper.
- The glass rod will attract the inflated balloon.
Conclusions:
- As the comb moves through the hair, it picks up excess electrons from the hair, resulting in a negative charge on the comb. When the negatively charged comb is brought near small pieces of paper, which are neutrally charged, the positive charges in the paper are attracted to the negative charges on the comb, causing the paper to be attracted to the comb.
- Similarly, when the glass rod is rubbed with the silk cloth, the glass rod becomes positively charged. When the rod is brought near the balloon, the negative charges in the balloon are attracted to the positive charges on the glass rod.
- These observations indicate that an atom is divisible and consists of charged particles.
“A. Comb dry hair. Does the comb then attract small pieces of paper?
B. Rub a glass rod with a silk cloth and bring the rod near an inflated balloon. Observe what happens.” – Solved.
Related Links:
Solution to Activity 4.1
Solution to Activity 4.2
Solution to Chapter 4 Structure of the Atom
