Question

Write a nuclear equation for beta decay :
A) Carbon-14
B) Sodium-24
C) Lead-210

Write a nuclear equation for alpha decay of:
A) Thorium-232
B) Uranium-234
C) Radium-223

Iodine has a half life of 8 hours. If a solution containing 5 grams of iodine-131 is injected into a patient, how long will it take until the total amount of iodine 131 left in the patient us 5 micro grams?

Answer 1

For beeta decays: there are 2 types of beeta decays, positive beeta decay and negative beeta decay.
Positive decay usually occurs in nuclei which has more protons and also the negative beeta decays occur in nuclei which have more neutrons.
negative beeta decay: A neutron will be broken down as follows
\[n \rightarrow Proton + negative beeta particle + neutrino \]
Positive beeta decay : A proton will be broken as follows
\[P \rightarrow Neutron + Positive beeta particle + neutrino \]
In both the decays when 1 proton is broken down a neutron is made and vise versa hence the no. of nucleons are constant for a given element.

Answer 2

Answers for the 1st part
1) Here the no. of neutrons are greater than the no. of protons hence it is a negative beeta decay. Thus the number of the proton increase by one \[C_{6}^{14} \rightarrow N_{7}^{14} + negative beeta particle + neutrino \]

2) It is again a beeta negative decay
\[Na_{11}^{24} \rightarrow Mg_{12}^{24} + Beetanegative particle + neutrino \]

3) It is also a negative beeta particle decay
\[Pb_{82}^{210} \rightarrow Bi_{83}^{210} + negative beeta particle + neutrino \]

Answer 3

An alpha particle decay always remove 2 protons and 2 neutrons.

1) \[Th_{90}^{232} \rightarrow Ra_{88}^{228} + \alpha \]

2) \[U_{92}^{234} \rightarrow Th_{90}^{230} + \]

3) \[Ra_{88}^{223} \rightarrow Rn_{86}^{219} +\]