Trivia
If you dig a 6 feet hole how deep is it?
6ft (20ft works too)
In Compton scattering, an X-ray photon scatters off this particle, treated as initially at rest and effectively free.
What is an electron?
Does Fission release or absorb energy?
It does both. Heavier nuclei that are unstable will undergo fission and release energy to become stable. Smaller nuclei that are already stable will require energy to split.
What are the products in a beta-plus decay?
daughter nucleus with 1 less proton (neutron is acceptable), positron, and neutrino.
Which two subatomic particles have no charge and negligible mass?
neutrinos and antineutrinos
Fear of long words
Hippopotomonstrosesquippedaliophobia
This scattering angle produces the maximum possible Compton wavelength shift, Δλ = 2λ_C.
What is 180°?
How will the time constant change if the number of starting radioactive atoms is doubled? How will the final number of radioactive atoms change at time t?
The time constant remains the same. The number left after time t will also double.
A heavy nucleus undergoes alpha and beta-minus decay. How have its atomic number, Z, and mass number, A, changed?
A decreased by 4
Z decreased by 1
What do antiparticles share in common with their counterparts?
Spin, mass, and opposite conserved charges
Bob has 2 apples. Tim eats 1 of those apples. What is the circumference of the sun?
2,715,396 miles
An X-ray with incident λ = 0.0700 nm scatters at θ = 60°; to three significant figures, this is the scattered photon’s wavelength λ′.
What is 0.0712 nm?
Two students debate radioactive decay:
Who is correct?
Student B is correct since radioactive decay is random.
True or False: Alpha decay can occur only if the mass of the daughter nucleus plus the mass of the alpha particle is less than the mass of the parent nucleus.
True since Mi > Mf + Ma, meaning the decay happened spontaneously as it is exothermic (releases energy through mass equivalence).
Name the 4 types of radioactive decay.
Gamma, beta minus, beta plus, and alpha
What is one incurable condition most asians have after getting into a good school that is evident on social media?
Advertising AI study tools on instagrams
In every Compton event, the scattered wavelength λ′ always satisfies this relationship to the incident λ — a direct consequence of energy conservation.
What is λ′ ≥ λ (greater than or equal to)?
What are the conditions that enable fusion to take place?
Since both nuclei will have positive charges, they repel. As a result, the nuclei must have a kinetic energy high enough (usually done by increasing temperature) to overcome repulsion for the nuclei to be close enough for the strong nuclear force to pull them together.
A nucleus of Radium-226 decays to Radon-222. A student claims that the Radon-222 nucleus plus the alpha particle that was emitted should equal the original mass of the Radium-226. Is this right or wrong and WHY?
Incorrect since some of the mass is converted into kinetic energy.
True or false: Mass is always conserved in beta decay
False
What is the airspeed velocity of an unladen swallow?
11 m/s (African or European Swallow? Works too)
Graphite electrons are bound, but during X-ray Compton scattering we treat them as free because the photon’s energy is far greater than this quantity.
What is the electron’s binding energy?
pIn a fusion reaction, deuterium and tritium combine to form helium-4 and a neutron.
Given:
Calculate:
m(i)=5.0301 u and m(f)=5.0113 u
change in m (mass defect)= 0.0188 u
E = 0.0188 times 931.5 = 17.51 MeV
Isotope A undergoes alpha decay with a half-life of 4 hours
Isotope B undergoes beta decay with a half-life of 3 hours
After 24 hours, what is N(A)/N(B) given that both isotopes have the same number of nuclei?
4
What is the term used for the number of electrons and neutrinos in a system that is conserved?
Lepton Number