Electric charge
All matter has Property of matter that causes a force when near another charge. Charge comes in two forms, positive and negative. For example, a negative charge causes a repulsive force on a neighbouring negative charge., in the same way that all matter has mass. All elements are made of atoms. An atom consists of a nucleus containing protons and neutrons, surrounded by electrons. have no overall charge - they are neutral. This is because atoms contain equal numbers of protons and electrons. Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons. carry a negative The electrical state of an object, which can be positively charged or negatively charged. and Subatomic particle with a positive charge and a relative mass of 1. The relative charge of a proton is +1. carry a positive electric charge.
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Static
Electrons can be made to move from one object to another. However, protons do not move because they are tightly bound in the Nuclei is the plural of nucleus. The nucleus is the central part of an atom. It contains protons and neutrons, and has most of the mass of the atom. of atoms.
For example, when a plastic rod is rubbed with a duster, electrons are When something is moved from one place to another. This may be people, objects or energy. from one material to the other. The material that gains electrons becomes negatively charged. The material that loses electrons becomes positively charged.
Image caption, The duster picks up electrons from the rod. This leaves the rod with a positive overall charge and the duster with a negative overall charge.
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Static charge occurs when electrons build up on an object. Static charge:
- can only build up on objects which are Material that does not allow charge or heat to pass through it easily., eg plastic or wood
- cannot build up on objects that act as An electrical conductor is a material which allows an electrical current to pass through it easily. It has a low resistance. , eg metals
Conductors allow the electrons to flow away, forming an The movement of electrically charged particles, for example, electrons moving through a wire or ions moving through a solution..
When a static charge on an object is discharged, an electric current flows through the air. This can cause sparks. Lightning is an example of a large amount of static charge being discharged.