Physics (AS & A Level) · Oct / Nov 2019 · Paper 12 · Question 38

The table gives some data relating to four neutral (uncharged) atoms W, X, Y and Z. | | W | X | Y | Z | |---|---|---|---|---| | nucleon (mass) number | 16 | 17 | 17 | 18 | | total number of particles (protons, neutrons and electrons) in the atom | 24 | 26 | 25 | 28 | Two of the atoms are isotopes of the same element. What is the proton number of this element?

1. A7
2. B8
3. C9
4. D10

As printed in the paper