Two ions, P and Q, are present in a hot gas. Each ion formed when one or more electrons were removed from a neutral atom.
| ion | number of protons | number of neutrons | number of electrons |
|---|---|---|---|
| P | 17 | 18 | 15 |
| Q | 17 | 20 | 16 |
Explain how the data show that the neutral atoms used to form P and Q were different isotopes of the same element.
Explain why ion P has a greater positive charge than ion Q.
Give the difference between the mass numbers of the neutral atoms used to form P and Q.
The table gives the energy of an electron when it occupies each of three allowed orbits in the neutral atom used to form Q.
| orbit | energy of electron in J |
|---|---|
| S | 2.4 × 10-19 |
| T | 6.1 × 10-19 |
| U | 9.2 × 10-19 |
An electron in orbit U returns to orbit S in two transitions, first to orbit T and then to orbit S.
Calculate the energy emitted as electromagnetic radiation in each of these two transitions.
A different electron is in orbit S. It absorbs 6.8 × 10-19 J of energy from electromagnetic radiation.
Explain which orbit this electron moves to.
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.