Why is an iron atom a different element than a sodium atom?
A) A sodium atom has fewer neutrons in its nucleus than an iron atom.
B) An iron atom has more protons in its nucleus than a sodium atom.
C) A sodium atom is bigger than an iron atom.
D) All of the above are true.

Question

Quizplus · Accepted Answer

The number of protons in the nucleus of an atom determines what element it is, and iron has more protons (26) than sodium (11). Choice A is incorrect because the number of neutrons can vary within an element, while the number of protons must stay the same. Choice C is also incorrect, as the size of an atom is determined by the size of its electron cloud, not the number of protons or neutrons in the nucleus.

Why Is an Iron Atom a Different Element Than a Sodium