Question: how many total electrons and valence electrons are found in an atom of f?
Answer: In fluorine, the highest energy level (or the outermost if you were to draw a Bohr model), is 2. So you add the 2 electrons in the 2s sublevel and the other 5 in the 2p sublevel and you get a total of 7 valence electrons. What is the number of atoms and number of electrons in 9.8 gm of N2O5?