Advertisements
Advertisements
Question
What is gamma decay?
Advertisements
Solution
Gamma rays are emitted by the parent nucleus. As you know, gamma ray is a high energy photons. The daughter nucleus is the same as the parent nucleus as no other particle is emitted, but it has less energy as some energy goes out in the form of the emitted gamma ray.
The electrons in an atom are arranged in different energy levels (orbits) and an electron from a higher orbit can make a transition to the lower orbit emitting a photon in the process. The situation in a nucleus is similar. The nucleons occupy energy levels with different energies. A nucleon can make a transition from a higher energy level to a lower energy level, emitting a photon in the process.
Usually, the nucleons in a nucleus are in the lowest possible energy state. They cannot easily get excited as a large amount of energy (in keVs or MeVs) is required for their excitation. A nucleon however may end up in an excited state as a result of the parent nucleus undergoing alpha or beta decay. Thus, gamma decays usually occur after one of these decays.
APPEARS IN
RELATED QUESTIONS
Describe alpha, beta and gamma decays and write down the formulae for the energies generated in each of these decays.
Complete the following equation describing nuclear decay.
\[\ce{_88^226Ra->_2^4\alpha {+}}\] ______.
Complete the following equation describing nuclear decay.
\[\ce{_8^19O->e^- { +}}\] _____
The half-life of 18F is 110 minutes. What fraction of 18F sample decays in 20 minutes?
The half-life of 35S is 87.8 d. What percentage of 35S sample remains after 180 d?
The half-life of 67Ga is 78 h. How long will it take to decay 12% of the sample of Ga?
65% of 111In sample decays in 4.2 d. What is its half-life?
The half-life of radon is 3.82 d. By what time would 99.9% of radon will be decayed?
In Hydrogen, the electron jumps from the fourth orbit to the second orbit. The wavenumber of the radiations emitted by an electron is ______
The half-life of a certain radioactive species is 6.93 × 105 seconds. What is the decay constant?
The half-life of a certain radioactive nucleus is 3.2 days. Calculate (i) decay constant (ii) average life of radioactive nucleus.
Show that for radioactive decay N(t) = `"N"_"O" "e"^{-λ"t"}`, where symbols have their usual meaning.
Obtain an expression for the half-lifetime of radioactive material. Hence state the relation between an average life and half life time of radioactive material.
A radioactive substance decays to (1/10)th of its original value in 56 days. Calculate its decay constant.
A radioactive nucleus emits 4 α-particles and 7 β-particles in succession. The ratio of number of neutrons of that of protons, is
[A = mass number, Z =atomic number]
Most excited states of an atom have life times of about ____________.
A radioactive substance has half life of 3 hours. 75 % of the substance would decay in ____________.
What is beta decay?
The graph obtained by plotting loge (A) [A is the activity of a radioactive sample] against t (time) out of the following is:
Show that the number of nuclei of a radioactive material decreases exponentially with time.
Define half-life period.
In one mean lifetime of a radioactive element the fraction of the nuclei that has disintegrated is ______. [e is the base of natural logarithm]
