What Is Mean By An Atom /pdf Document

The Nuclear Regulatory Commissions Science 101: What is an Atom? The atom is considered the basic building block of matter. Anything that has a mass in other words, anything that occupies spaceis composed of atoms. While its name originally referred to a particle that couldnt be divided any more the smallest thing possiblewe now know that each atom is generally made up of smaller particles. Given that these particles make up atoms, they are often referred to as subatomic particles. There are three subatomic particles: protons, neutrons and electrons. Two of the subatomic particles have electrical charges: protons have a positive charge while electrons have a negative charge. Neutrons, on the other hand, dont have a charge. A fundamental rule is that particles with the same charge are repulsed from each other, while particles with opposite charges are attracted to each other. So, much like opposite ends of a magnet, protons and electrons are attracted to each other. Likewise, just as when you experi ence resistance trying to push the same ends of two magnets together, protons are repelled from other protons and electrons are repelled from other electrons. The nucleus (or center) of an atom is made up of