Question: how many electrons are in an atom of uranium−238 uranium−238?
Answer: Write the symbol for this isotope. The atomic number of uranium (see periodic table) is 92, and the mass number of the isotope is given as 238. Therefore, it has 92 protons, 92 electrons, and 238 — 92 : 146 neutrons. Its symbol is U23892 (or 238U).