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