Which change occurs in the nucleus of a radioactive atom when a positron (β+\beta^+β+ particle) is emitted?
proton→neutron+positron\text{proton} \rightarrow \text{neutron} + \text{positron}proton→neutron+positron
neutron→proton+positron\text{neutron} \rightarrow \text{proton} + \text{positron}neutron→proton+positron
proton→neutron+electron\text{proton} \rightarrow \text{neutron} + \text{electron}proton→neutron+electron
neutron→proton+electron\text{neutron} \rightarrow \text{proton} + \text{electron}neutron→proton+electron
120 exam-style questions on CIE IGCSE Physics 5.2.3a Radioactive decay. Each one has a worked solution and a mark scheme showing where the marks go.