Electrical charges

1/ Two kinds of electrical charges are negative charges and positive charges

2/ The law of electrical charges: like charges repel one another, unlike charges attract one another, charged objects attract neutral objects.

3/ Electrostatics refers to electric charges that are stationary or at rest.  Friction causes electrons to get knocked off one material and transferred to the other material.  Because one object now has less electrons then protons, it is negatively charged.  Contact charges involves a charged object making direct contact  with a neutral object.  If the neutral object is negative, electrons can flow into the neutral object, the neutral object becomes negatively charged

4/ Conductors, such as  metals are substances that allow charges to move freely through the object.  Conductors allow electrical charge.  Insulators such as Mon metals are substances that do not allow charged to move freely through the object.  Insulators can protect people from being electrocuted.