The center of an atom is called the nucleus. The nucleus is made up of particles called and neutrons. spin around the nucleus in shells. The protons and electrons of an atom are attracted to each other. They both carry an electrical charge. Protons have a positive charge (+) and have a negative charge (-). The positive charge of the protons is equal to the charge of the electrons. Opposite charges each other. The electrons in the shells closest to the nucleus have a strong force of to the protons. Sometimes, the electrons in an atom's outermost shells do not have a strong force of to the protons. These electrons can be pushed out of their orbits. Applying a force can make them shift from one atom to another. These shifting electrons are . Remember, opposite charges each other, like charges repel each other. Word Bank:
