What is the atomic number of sodium? Chemistry Matter Atomic Number 1 Answer anor277 Sep 15, 2016 Got a Periodic Table? Explanation: For sodium metal, #Z=11#. That is there are 11 protons, 11 massive, positively charged particles in the element's nucleus. How does this help you? Answer link Related questions How can the atomic number be determined? How can the atomic mass of an element be calculated? How do atomic numbers change in the periodic table? What is the atomic mass in hydrogen? What does the atomic number tell us? Why is the atomic number used to identify elements? Why is the atomic number a whole number? Why is atomic number represented by Z? How did Dmitri Mendeleev contribute to the atomic number? How is the atomic number affected by gamma decay? See all questions in Atomic Number Impact of this question 4559 views around the world You can reuse this answer Creative Commons License