‘Making and breaking nuclei’ describes the process by which the atomic elements came to be in the early universe. The heat energy in the big bang, some 13.7 billion years ago, converted into counterbalanced particles of matter and antimatter. The seeds of atomic nuclei were initially the simplest constituents: quarks. During the last 5 billion years, the majority of elements found on earth were formed inside a long-dead star, where they were all cooked from protons, which were synthesised within the first second of the universe. The processes of stellar nucleosynthesis, the CNO cycle, supernovae nucleosynthesis, and cosmic spallation are explained along with the dating of the age of the Earth.