Atoms are the microscopic building blocks of the universe. They make up almost ANY material including solids, liquids, and gases! A human has more than 1 billion atoms! Atoms have specific parts. There is the nucleus, which is the center of the atom. Then, there are even smaller parts. They are protons, neutrons, and electrons! Protons are a small part of the atom that is located in the nucleus or the center of the atom. Protons are positively charged. Then, there are neutrons. They are also located in the nucleus. Neutrons have no charge at all. That leaves the nucleus of the atom positively charged. Then, there are electrons. Electrons have a negative charge. Electrons orbit or circle around the nucleus. That is what an atom is!