Half-Life
What is the equation for the half-life decay constant?
λ = ln2/t1/2
This equation, formulated by Einstein, relates mass and energy.
What is E = mc²?
What are the 4 types of nuclear decay?
Alpha, Beta-minus, Beta-plus, and gamma decay
The time it takes for half of the initial nuclei in a sample to decay.
What is half-life?
The empty prompt space challenges the notion of expectations. Scientists and physicists such as yourself approach certain issues expecting definitive and objective truths and realities. However, this hinders the creative and abstract nature of the human mind. In the presence of absence, there is completeness. How will you find completeness?
Half-life measures the time it takes for this type of decay.
radioactive
What is the equivalent energy of a neutron in Joules? The mass of a neutron is around 1.67x10^-27 kg
What is 1.5x10^-10 J?
A radioactive sample has an initial activity of 400 Bq. After 12 hours, it has 50 Bq. What is the half-life?
4 hours
Which two subatomic particles have no charge and negligible mass?
What are neutrinos and antineutrinos?
Which of the following does Mr. Holloway say he isn't in his syllabus?
guide, mentor, friend, or colleague
friend
Radioactive element X has a half-life of approximately 50 days. Radioactive element Y has a half-life of approximately 100 days. A 0.8 g sample of element X and a 0.8 g sample of element Y are weighed and examined. Some time later, both samples are measured again and 0.2 g of element X remains. How much of element Y remains?
0.4 g
An electron and a neutron both convert completely into energy. Which one produces more energy?
What is a neutron?
A graph comparing binding energy per nucleon with mass number shows that a heavy nucleus moves toward higher binding energy per nucleon after decay.
What type of decay could have occurred?
alpha and beta-minus decay only
This type of fission indicates a higher binding energy.
What is induced fission?
True or False: Mr. Holloway has a middle school picture of himself on the canvas homepage.
False
A sample of Mendelevium-258 with 3000 atoms has a mean lifetime e-1=37% of around 51.5 days. Approximately how many nuclei remain after 2 weeks?
2289 nuclei
A nucleus at rest splits into two smaller nuclei. The total mass of the products is less than the original nucleus. Rank the following energies.
The total energy of the original nucleus > total energy of the product nuclei > kinetic energy of the product nuclei
A radioactive isotope X undergoes the following decay:
X -> Y + α
Y -> Z + β(-)
Z -> W + β(+)
If the original nucleus X has atomic number 92 and mass number 238, what are the atomic number and mass number of nucleus W?
Z=90, A=234
This type of decay emits a neutrino.
What is beta-plus decay?
Where did Mr. Holloway teach before Westlake High School?
El Camino High School
The Geiger counter clicks when it detects ionizing radiation but does not distinguish between alpha, beta, and gamma particles. The number of clicks indicates the number of ionizing events happening in the Geiger counter device due to the radiation it receives. If the half-life of the radioactive material being investigated is 12 hours, what will happen to the click rate of the Geiger counter after 3 days?
the click rate on the Geiger counter would be reduced by a factor (1/64)
Find the energy released in the alpha decay of 23892U Hint: You will need the following values: 23490Th has a mass of 3.8864x10^-25 kg, 4He has a mass of 6.6446x10^-27 kg, and 23892U has a mass of 3.9529x10^-25kg
What is 4.86x10^-13?
Isotope A undergoes alpha decay with a half-life of 4 hours
Isotope B undergoes beta decay with a half-life of 2 hours
After 8 hours, what is N(A)/N(B) given that both isotopes have the same number of nuclei?
2
Probability per unit time that a specific radioactive nucleus will decay
What is the decay constant?
What is the name of Mr. Holloway's wife and children?
Vicki, Caden, and Jenna