The ratio of neutrons to protons of an element having a mass number and atomic number of 80 and 40 respectively is ___________________? August 25, 2021March 6, 2019 by admin The ratio of neutrons to protons of an element having a mass number and atomic number of 80 and 40 respectively is ___________________? A. 1 B. 0.5 C. 2 D. 4