- [Hard]A wooden artefact recovered from an excavation shows a carbon-14 activity that is one-fourth of the activity in living wood, and an archaeologist esti...
- [Hard]A researcher considers a singly ionised helium ion with atomic number two behaving like a hydrogen-like system, and asks for the energy of its ground ...
- [Medium]The Sun generates its enormous power by fusing hydrogen nuclei into helium at its core, and a student is asked why fusion requires extremely high temp...
- [Medium]In a nuclear reactor, a uranium-235 nucleus captures a slow neutron and splits into lighter fragments, and an engineer explains what makes the resulti...
- [Easy]Following an alpha or beta emission, a daughter nucleus is often left in an excited state and subsequently releases a gamma ray, and a learner must id...
- [Medium]A neutron-rich nucleus undergoes beta-minus decay inside a detector, and a student is asked what particles are emitted alongside the transformed nucle...
- [Medium]A radioactive isotope used in medical imaging has a half-life of 6 hours, and a technician needs its decay constant so the activity can be predicted a...
- [Medium]Given that the mass defect of a helium-4 nucleus is about 0.0304 u, an examiner asks candidates to find the total binding energy of the nucleus in meg...
- [Easy]Looking at the binding-energy-per-nucleon curve, a student notices it peaks near a certain mass number, indicating the most stable nuclei, and is aske...
- [Easy]A radioactive sample initially contains 8 billion nuclei of an unstable isotope, and after three successive half-lives elapse a monitor records the nu...
- [Medium]A freshly prepared source contains a large number of identical unstable nuclei, and a researcher observes that its activity is defined as the rate at ...
- [Easy]When a heavy parent nucleus undergoes alpha decay, it emits a helium nucleus, and a student must state how the atomic number and mass number of the da...
- [Medium]A helium-4 nucleus is assembled from two protons and two neutrons, and the measured nuclear mass falls short of the sum of the free particle masses by...
- [Easy]A lab worksheet asks students to compute the energy equivalent of one atomic mass unit of matter using Einstein's mass-energy relation, expressed in m...
- [Easy]A chemistry-physics bridge lesson considers the isotope of iron written as iron-56 with atomic number 26, and asks how many neutrons its nucleus conta...
- [Medium]A physics teacher explains that the shortest wavelength line of a particular hydrogen series corresponds to the series limit, and asks which series ha...
- [Medium]A nuclear physicist estimates the radius of a nucleus containing 125 nucleons using the empirical size relation, and reports the value in femtometres....
- [Easy]During a gold-foil alpha scattering demonstration, only a very small fraction of alpha particles are deflected through large angles, which led Rutherf...
- [Medium]An electron in a hydrogen atom drops from the third energy level to the second, and a spectroscopist wants the energy of the emitted photon in electro...
- [Easy]In the Bohr model of a hydrogen atom, an electron orbits the nucleus in the second allowed stationary orbit, and a student wishes to know the radius o...
- [Medium]Bohr radius a0 approximately equals?...
- [Easy]Energy of nth level of hydrogen atom En equals?...
- [Hard]Photon frequency for transition n=3 to n=2 in H: ν =? (E_n = -13.6/n² eV; h = 4.14×10^{-15} eV·s)...
- [Easy]Isotopes are nuclei with same?...
- [Medium]Mass defect corresponds to?...
- [Medium]Binding energy per nucleon highest around?...
- [Easy]Number remaining after time t: N =? (Initial N0, decay constant λ)...
- [Easy]Half-life T1/2 in terms of λ equals?...
- [Medium]Nuclear radius R approximated by?...
- [Medium]Relative penetration power (highest)?...
- [Hard]Energy production mechanism: fusion of light nuclei and fission of heavy both release energy because?...
- [Medium]Rutherford scattering showed nucleus is?...
- [Hard]Bohr postulate: angular momentum quantized as?...
- [Medium]In beta minus (β−) decay a neutron converts to?...
- [Easy]Activity A of sample equals?...