CHEMISTRY · Single correct · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
Atom X has 26 protons, 30 neutrons, and 24 electrons. Atom Y has 26 protons, 32 neutrons, and 26 electrons. Which of the following best describes the relationship between atoms X and Y?
(a) They are isotopes of the same element; both atoms are 2− ions.
(b) They are isobars because they share the same mass number of 58; atom X is a 2+ ion and atom Y is neutral.
(c) They are isotopes of the same element; atom X is a 2+ ion and atom Y is neutral.
(d) They are different elements because atom X has fewer electrons; atom X is neutral and atom Y is a 2− ion.