Physics
Curium is a radioactive element with the symbol named in honour of Madam Curie. The graph of number of protons vs number of neutrons for some elements are shown below : (a) Which point on the graph indicates the element Cm? (b) Which point on the graph indicates daughter nucleus after Cm undergoes radioactive decay of 1α followed by 2β? (c) State the mass number of the daughter nucleus.
Answer
(a) As, Curium has 96 protons and 247 – 96 = 151 neutrons and point P represents 96 protons and 151 neutrons. Hence, P point indicates element Curium.
(b) After the radioactive decay of 1 α and 2 β particles, the atomic number and mass number of daughter nucleus will be 243 and 96 respectively. So, it will have 243 – 96 = 147 neutrons.
As, point R represents 96 protons and 147 neutrons. Hence R point indicates the daughter nucleus.
(c) Mass number of daughter nucleus = Mass number of Curium – Mass number of α particle = 247 – 4 = 243
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