An atom of the element iron has an atomic number of 26 and an atomic mass number of 56. If it is neutral, how many protons, neutrons, and electrons does it have?
A) 26 protons, 30 neutrons, 26 electrons
B) 26 protons, 30 neutrons, 30 electrons
C) 26 protons, 56 neutrons, 26 electrons
D) 13 protons, 43 neutrons, 13 electrons
E) 13 protons, 56 neutrons, 13 electrons

Question

Quizplus · Accepted Answer

The atomic number of iron is 26, which means it has 26 protons. The atomic mass number is 56, which means it has 56 nucleons (protons and neutrons) in total. To find how many neutrons it has, we subtract the atomic number (26) from the atomic mass number (56), giving us 30 neutrons. Since an atom is neutral, it has the same number of electrons as protons, so it also has 26 electrons. Therefore, the correct answer is A.

An Atom of the Element Iron Has an Atomic Number