An ion source produces a beam containing ions R and S. The ions are formed from different isotopes of the same element.
| Ion | Information |
|---|---|
| R | contains 14 electrons and 20 neutrons; formed when three electrons were removed from a neutral atom |
| S | has mass number 39 and relative charge +2 |
Calculate the number of electrons and the number of neutrons in ion S.
Compare the approximate masses of ions R and S. Ignore the mass of the electrons.
103 exam-style questions on Edexcel GCSE Physics 6.1 Atomic structure and isotopes, covering 6.1.1 Structure of the atom, 6.1.2 Isotopes: atomic and mass number, 6.1.3 Sub-atomic particles: masses and charges, and 6.1.4 Electron orbits and energy changes. Each one has a worked solution and a mark scheme showing where the marks go.