Various rules of thumb have seen proposed by the scientific community to expalin the mode of radioactive decay by various radioisotopes. One of the major rules is called the `n//p` ratio. If all the known isotopes of the elemnts are plotted on a graph of number of neutrons (n) versus number of protons (p), it is observed that all isotopes lying outside of a 'stable' `n//p` ratio region are radioactive as shown f The graph exhibits straight line behaviour with unit slope up to `p=25`. Above `p=25`, tgose isotopes with `n//p` ratios lying above the stable region usually undergo beta decay. Very heavy isotopes `(pgt83)` are unstable because of their relativley large nuclei and they undergo alpha decay. Gamma ray emission does not involve the release of a particle. It represnts a change in an atom from a higher energy level to a lower energy level. `Th-230` undergoes a series of radioactive decay processes resulting in `Bi-214` being the final product. What was the sequence of the processes that occured?A. `alpha,alpha,alpha,g,beta`B. `alpha,alpha,alpha,alpha,beta`C. `alpha,alpha,beta,beta`D. `alpha,beta,beta,beta,gamma`

Various rules of thumb have seen proposed by the scientific community

1.	Various rules of thumb have seen proposed by the scientific community to expalin the mode of radioactive decay by various radioisotopes. One of the major rules is called the `n//p` ratio. If all the known isotopes of the elemnts are plotted on a graph of number of neutrons (n) versus number of protons (p), it is observed that all isotopes lying outside of a 'stable' `n//p` ratio region are radioactive as shown f The graph exhibits straight line behaviour with unit slope up to `p=25`. Above `p=25`, tgose isotopes with `n//p` ratios lying above the stable region usually undergo beta decay. Very heavy isotopes `(pgt83)` are unstable because of their relativley large nuclei and they undergo alpha decay. Gamma ray emission does not involve the release of a particle. It represnts a change in an atom from a higher energy level to a lower energy level. `Th-230` undergoes a series of radioactive decay processes resulting in `Bi-214` being the final product. What was the sequence of the processes that occured?A. `alpha,alpha,alpha,g,beta`B. `alpha,alpha,alpha,alpha,beta`C. `alpha,alpha,beta,beta`D. `alpha,beta,beta,beta,gamma`
Answer» Correct Answer - b `._(90)^(230)Th rarr ._(83)^(214)Bi + x._(1)^(0)e^(bar) +y._(2)^(4)He^(2+)+z ("gamma ray")` Since the sum of the atomic numbers and mass numbers on either side of the equation must be equal (matter cannot be created or destroyed),we get `90=83-x+2y` and `230=214+4y` Solving, we get `y=4` and `x=1` The order of the reactions is irrelevant (i.e., `alpha, beta`,...) Since gamma rays have no atomic number or mass number, the value of z does not affect this particular calculation.

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