Cobalt-60 is a radioactive isotope of cobalt widely used in industrial radiography and cancer radiotherapy. A neutral atom of Cobalt-60 contains 27 protons and 33 neutrons.
Which of the following nuclides represented by X\text{X}X is also an isotope of cobalt?
2860X^{60}_{28}\text{X}2860X
2657X^{57}_{26}\text{X}2657X
2757X^{57}_{27}\text{X}2757X
2859X^{59}_{28}\text{X}2859X
41 exam-style questions on OCR GCSE Physics Radioactive emissions. Each one has a worked solution and a mark scheme showing where the marks go.