A sample contains 96 g of a radioactive isotope. The half-life of this isotope is 15 hours15\text{ hours}15 hours.
Calculate the mass of the original radioactive isotope remaining after 45 hours45\text{ hours}45 hours.
90 exam-style questions on Edexcel GCSE Physics 6.3 Nuclear equations and decay, covering 6.3.1 Beta-minus and beta-plus decay, 6.3.2 Effects of decay on the nucleus, and 6.3.3 Balancing nuclear equations. Each one has a worked solution and a mark scheme showing where the marks go.