* Protons: These are positively charged particles located in the nucleus of the atom. The number of protons defines the element. Astatine has 85 protons.
* Neutrons: These are neutral particles also located in the nucleus. The number of neutrons can vary within an element, creating isotopes. Astatine has several isotopes, with the most stable having 125 neutrons.
* Electrons: These are negatively charged particles that orbit the nucleus in shells or energy levels. Atoms have an equal number of protons and electrons, so astatine has 85 electrons.
Let me know if you'd like to know more about the structure of astatine or its isotopes!
