Paper 2 · Atomic structure, ions and covalent bonding
Fig. 1 shows structures of four atoms/ions, A, B, C and D, drawn as nucleus-and-shell diagrams. Structures A and D have the same number of protons but different numbers of neutrons. Which two structures together represent a pair of isotopes?
AA and D
BA and B
CB and C
DC and D
Explanation: Fig. 1's structures A and D have the same number of protons but different numbers of neutrons, making them isotopes of the same element.
Derived from ZIMSEC Chemistry 5071/2 Paper 2 Theory, November 2013, Q1
