A geologist reconstructs part of a decay chain in a mineral sample. The product at the end of this part has mass number 206 and atomic number 82. This product was made by alpha decay of an intermediate nucleus. The intermediate nucleus was made by beta-minus decay of the parent nucleus.
What is the neutron number of the parent nucleus?
124124124
125125125
126126126
127127127
120 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.