A team of scientists studying a material have determined that 12C, 13C, and 14C occur in the material in a ratio of 1000:10:1. How did they most likely differentiate between these forms of carbon?
O by the number of neutrons in 12C, 13C, and 14C
O by the number of electrons in 12C, 13C, and 14C
O by the number of positrons in 12C, 13C, and 14C
O by the biomasses of 12C, 13C, and 14C
O by the number of protons in 12C, 13C, and 14C