Experiment: Rub a balloon with a piece of cloth and gradually move it to a pinch of pepper salt scattered on the ground
Observation: The balloon gradually pulls up the pepper salt straightly despite the gravity of the Earth. The pepper salt stays stuck there for a while before suddenly falls off on the ground.
Explanation: Rubbing the balloon with a piece of cloth adds electrons to the balloon and causes it to become negatively charged. Like charges repel (the two balloons, once charged, will move away from each other) and opposite charges attract. The positively charged pepper salt is attracted to the negatively charged balloon and starts to rise up to meet it.