The diagram shows the symbols for four atoms, W, X, Y and Z. The letters are not the real symbols of the elements.

Statement 1: X and Y are isotopes of the same element.
Statement 2: W and Z are isotopes of the same element, because they have the same mass number.
Statement 3: Y and Z have the same number of neutrons.
Statement 4: An atom of W has more neutrons than an atom of X.
Which statements are correct?
1 and 3 only
1, 3 and 4 only
2 and 3 only
1, 2 and 4 only
51 exam-style questions on OCR GCSE Chemistry 1.2 Atomic structure, covering 1.2.1 Development of the atomic model, 1.2.2 The nuclear model and the size of atoms, and 1.2.3 Subatomic particles in atoms and ions. Each one has a worked solution and a mark scheme showing where the marks go.