Physics » Electric Charges and Fields » Quantization Of Charge

# Summary and Main Ideas

## Summary

• There are two kinds of charge: positive and negative.

• Positive charge is carried by protons in the nucleus.

• Negative charge is carried by electrons.

• Objects can be positively charged, negatively charged or neutral.

• Objects that are neutral have equal numbers of positive and negative charge.

• Unlike charges are attracted to each other and like charges are repelled from each other.

• Charge is neither created nor destroyed, it can only be transferred.

• Charge is measured in coulombs ($$\text{C}$$).

• Charge is quantised in units of the charge of an electron $$-\text{1.6} \times \text{10}^{-\text{19}}$$ $$\text{C}$$, $$Q=n{q}_{e}$$

• Conductors allow charge to move through them easily.

• Insulators do not allow charge to move through them easily.

• Identical, conducting spheres in contact share their charge according to:

$Q=\frac{{Q}_{1}+{Q}_{2}}{2}$

 Physical Quantities Quantity Unit name Unit symbol Charge (Q) coulomb $$\text{C}$$ Charge on the electron ($${q}_{e}$$) coulomb $$\text{C}$$

Table: Units used in electrostatics