Neutrons and protons make up a nucleus and they are in the middle of an atom. Electrons surround the nucleus. Opposite charges attract each other. Because of this, protons do not attract other protons and electrons do not attract other electrons. Instead, protons attract electrons and electrons attract protons. When someone looks at the elements on the periodic table, they can see how many protons are present by looking at the atomic number. Since atoms have to have an equal amount of each, if an element contains 36 protons, it also has 36 electrons.
