Advertisements
Advertisements
Question
Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of `""_88^226 "Ra"`.
Given `"m"(""_88^226"Ra")` = 226.02540 u, `"m"(""_86^222 "Rn")` = 222.01750 u,
`"m"(""_86^220 "Rn")`= 220.01137 u, `"m"(""_84^216 "Po")`= 216.00189 u.
Advertisements
Solution
Alpha particle decay of `""_88^226"Ra"` emits a helium nucleus. As a result, its mass number reduces to (226 − 4) 222 and its atomic number reduces to (88 − 2) 86. This is shown in the following nuclear reaction.
\[\ce{^226_88 Ra -> ^222_86 Ra + ^4_2He}\]
Q-value of
emitted α-particle = (Sum of initial mass − Sum of final mass) c2
Where,
c = Speed of light
It is given that:
`"m"(""_88^226"Ra")` = 226.02540 u
`"m"(""_86^222"Rn")` = 222.01750 u
`"m"(""_2^4"He")` = 4.002603 u
Q-value = [226.02540 − (222.01750 + 4.002603)] u c2
= 0.005297 u c2
But 1 u = 931.5 MeV/c2
∴ Q = 0.005297 × 931.5 ≈ 4.94 MeV
Kinetic energy of the α-particle = `("Mass number after decay"/"Mass number before decay") xx "Q"`
` = 222/226 xx 4.94 = 4.85 " MeV"`
RELATED QUESTIONS
In the study of Geiger-Marsdon experiment on scattering of α particles by a thin foil of gold, draw the trajectory of α-particles in the coulomb field of target nucleus. Explain briefly how one gets the information on the size of the nucleus from this study.
From the relation R = R0 A1/3, where R0 is constant and A is the mass number of the nucleus, show that nuclear matter density is independent of A
Two stable isotopes of lithium `""_3^6"Li"` and `""_3^7"Li"` have respective abundances of 7.5% and 92.5%. These isotopes have masses 6.01512 u and 7.01600 u, respectively. Find the atomic mass of lithium.
Write one balanced equation to show Emission of `beta^-` (i.e. a negative beta particle)
The mass number of a nucleus is
The atomic mass of Uranium `""_92^238"U"` is 238.0508 u, while that of Thorium `""_90^234"Th"` is 234.0436u, and that of Helium `""_2^4"He"` "is 4.0026u. Alpha decay converts `""_92^238"U"` into `""_92^234"Th"` as, shown below:
`""_92^238"U" -> ( ""_90^234"Th" + ""_2^4"He" + "Energy" )`
Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of `""_86^220"Rn"`.
Given `"m"(""_88^226"Ra")` = 226.02540 u, `"m"(""_86^222 "Rn")` = 222.01750 u,
`"m"(""_86^220 "Rn")`= 220.01137 u, `"m"(""_84^216 "Po")`= 216.00189 u.
\[\ce{^197_79Au}\] contains ______.
The nuclei of isotopes of a given element contain the same number of ______.
The valance electrons in alkali metal is a:-
The mass number of a nucleus is equal to the number of:-
Are the nucleons fundamental particles, or do they consist of still smaller parts? One way to find out is to probe a nucleon just as Rutherford probed an atom. What should be the kinetic energy of an electron for it to be able to probe a nucleon? Assume the diameter of a nucleon to be approximately 10–15 m.
A nuclide 1 is said to be the mirror isobar of nuclide 2 if Z1 = N2 and Z2 = N1. (a) What nuclide is a mirror isobar of 1123 Na? (b) Which nuclide out of the two mirror isobars have greater binding energy and why?
Before the neutrino hypothesis, the beta decay process was throught to be the transition, `n -> p + vece`. If this was true, show that if the neutron was at rest, the proton and electron would emerge with fixed energies and calculate them. Experimentally, the electron energy was found to have a large range.
Two nuclei may have the same radius, even though they contain different numbers of protons and neutrons. Explain.
What is ‘Pair production’?
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about:
In his experiment verifying neutral matter inside the nucleus, James Chadwick observed neutral radiation when beryllium nuclei were bombarded with:
A proton or a neutron is collectively called a:
Regarding the stability of the neutron, which statement is correct?
Isotopes have identical chemical behaviour because:
