A nuclide of an alkaline earth metal undergoes radioactive decay by emission of three -particles in succession. The group of the periodic table to which the resulting daughter element would belong is
- Gr. 13
- Gr. 17
- Gr. 14
- Gr. 16
Answer
(3) Gr. 14
Solution
An alkaline earth metal belongs to group 2 (valence shell ns2).
Emission of one -particle ( 42He ) lowers the atomic number by 2
three -particles lower it by 3 2 = 6
Counting back 6 places from a group 2 element: group 1, then groups 18, 17, 16, 15, 14 of the previous period.
e.g. 22688Ra -3 21482Pb (group 14)
The daughter element belongs to group 14.
Answer: (3)