How many electrons, protons, and neutrons does an iron-55 atom have
A) 26 electrons, 26 protons, and 29 neutrons
B) 55 electrons, 26 protons, and 29 neutrons
C) 26 electrons, 55 protons, and 29 neutrons
D) 26 electrons, 26 protons, and 55 neutrons
E) 29 electrons, 26 protons, and 26 neutrons

Question

Quizplus · Accepted Answer

Iron (Fe) has an atomic number of 26, which means it has 26 protons and, in a neutral atom, 26 electrons. The mass number of iron-55 is 55, which is the sum of protons and neutrons. Therefore, to find the number of neutrons: 55 (mass number) - 26 (number of protons) = 29 neutrons.

How Many Electrons, Protons, and Neutrons Does an Iron-55 Atom