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A nuclide of an alkaline earth metal undergoes radioactive decay by emission of the α-particle in succession. The group of the periodic table to which the resulting daughter element would belong is:

1. Gr. 4
2. Gr. 6
3. Gr. 14
4. Gr. 16

Correct answer: Gr. 14

Solution

When an α-particle is emitted, the atomic number decreases by 2 and the mass number decreases by 4. Since the original element is an alkaline earth metal, which has an atomic number of 2 or 12, the resulting daughter element will have an atomic number of 0 or 10. Therefore, it will belong to group 14.

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