Section 1.2: Quantization of Charge
This section explains the concept of quantized electric charge, introducing the elementary charge \( e \), and showing how charges occur in discrete multiples of \( e \).
Quantization of Charge:
All observable charges are integer multiples of the elementary charge:
\( q = n e \), where \( n = 0, \pm1, \pm2, \dots \) and \( e = 1.602 \times 10^{-19} \, \mathrm{C} \)
Example 1
If an object has a charge of \( 4.8 \times 10^{-19} \, \mathrm{C} \), determine how many excess electrons it has.
Number of electrons: \( n = \frac{q}{e} = \frac{4.8 \times 10^{-19}}{1.602 \times 10^{-19}} \approx 3 \)
Practice Problems
- An object has a charge of \( 9.6 \times 10^{-19} \, \mathrm{C} \). How many excess electrons does it have?
- Calculate the charge on a particle if it has lost 5 electrons.
- A small sphere contains 2.5 × 10¹² electrons more than protons. Determine its net charge.
- Explain why charge always appears as multiples of \( e \) in isolated systems.
- Determine the total charge for 10³ electrons added to a neutral object.