Atom X has 17 electrons, 17 protons, and 18 neutrons.
Atom Y has 17 electrons, 17 protons, and 20 neutrons.
Which statement is correct?
Atom X has atomic number 35.
Atom Y has nucleon number 37.
Atom X has nucleon number 18.
Atoms X and Y are different chemical elements.
170 exam-style questions on CIE IGCSE Physics 5.1.2a Composition of the nucleus and isotopes. Each one has a worked solution and a mark scheme showing where the marks go.