- [Medium]A heavy nucleus of mass number 240 with binding energy per nucleon 7.6 MeV splits into two fragments, each having binding energy per nucleon 8.5 MeV. ...
- [Medium]A radioactive sample initially registers an activity of 8000 disintegrations per second on a detector. If the isotope has a half-life of 15 days, what...
- [Easy]A freshly prepared radioactive source is left to decay for a period equal to three of its half-lives. What fraction of the original radioactive nuclei...
- [Medium]A particular radioactive isotope is measured to have a half-life of 6.93 hours. Based on the relationship between half-life and average lifetime, what...
- [Medium]A uranium-238 nucleus with atomic number 92 first emits an alpha particle and subsequently undergoes two successive beta-minus decays. What is the ato...
- [Easy]On the curve of binding energy per nucleon plotted against mass number, one element sits at the peak and represents the most stable nuclear configurat...
- [Medium]Two nuclei have mass numbers 27 and 125 respectively, and both obey the standard nuclear radius relation. What is the ratio of the nuclear mass densit...
- [Easy]A sample of excited hydrogen atoms has its electrons populating the fourth energy level. As these electrons cascade down to the ground state through a...
- [Easy]Experiments show that the radius of an atomic nucleus depends on its mass number through R = R0 A^(1/3), with R0 = 1.2 fm. What is the approximate rad...
- [Medium]A helium-4 nucleus is assembled from two protons and two neutrons. Using mass of hydrogen atom 1.00783 u, neutron 1.00867 u, and helium-4 atom 4.00260...
- [Medium]A hydrogen electron occupies the third Bohr orbit, where its orbital speed is smaller than in the ground state. If the ground-state orbital speed is 2...
- [Medium]According to de Broglie's interpretation of stationary states, a standing electron wave exactly fits around each Bohr orbit. For the second orbit of h...
- [Medium]A hydrogen atom initially in its ground state absorbs a photon and its electron jumps to the second excited state with principal quantum number three....
- [Medium]When the electron in a hydrogen atom drops from the third energy level to the second energy level, a visible red photon is emitted. What is the wavele...
- [Easy]Consider a hydrogen atom whose electron has been raised to the first excited state corresponding to principal quantum number two. What is the total en...
- [Easy]In the Bohr model of the hydrogen atom, an electron is found in the third allowed stationary orbit. What is the radius of this orbit, given that the g...
- [Medium]Using Rydberg formula, what is the wavelength of light emitted when an electron in hydrogen atom transitions from n = 3 to n = 2? (R = 1.097 × 10⁷ m⁻¹...
- [Easy]In Rutherford's α-particle scattering experiment, most alpha particles pass through the gold foil undeflected because:...
- [Easy]Two isotopes of an element differ in:...
- [Medium]In a nuclear fission reaction, if the binding energy per nucleon increases from 7.6 MeV to 8.5 MeV, and 200 nucleons are involved, what is the energy ...
- [Easy]The decay constant of a radioactive substance is 0.693 per day. What is its half-life?...
- [Easy]In the nuclear reaction ²³⁸₉₂U → ²³⁴₉₀Th + X, what is X?...
- [Easy]The wavelength of the first line of Balmer series in hydrogen spectrum is 656 nm. This transition is from n = 3 to:...
- [Easy]The half-life of a radioactive substance is 10 days. What fraction of the original amount will remain after 30 days?...
- [Easy]In which orbit of hydrogen atom does the electron have an energy of -3.4 eV?...
- [Easy]Energy of nth Bohr orbit in hydrogen-like ion (atomic number Z) scales as:...
- [Easy]Bohr radius a_0 for hydrogen represents:...
- [Easy]Ionization energy corresponds to energy required to move electron from ground state to:...
- [Easy]Balmer series of hydrogen arises from transitions ending at:...
- [Easy]Nucleons in nucleus refer to:...
- [Medium]Mass defect arises because total mass of nucleus is:...
- [Medium]High binding energy per nucleon implies nucleus is:...
- [Medium]Radioactive decay law states N(t) = N_0 e^{-λ t} where λ is:...
- [Medium]Half-life T_{1/2} relates to decay constant by:...
- [Hard]Alpha decay reduces mass number by:...
- [Hard]In beta minus decay, atomic number Z changes by:...
- [Hard]Gamma emission typically follows nuclear reaction to:...
- [Hard]Nuclear force is characterized by being:...
- [Hard]Energy released in nuclear reaction given mass defect Δm is:...
- [Hard]Activity A of sample defined as:...