U-236 is an important neutron poison in reactors that is created
in uraniumbased fuels from U-235 capturing a neutron. Derive an
expression for the time at which the peak U-236 concentration
occurs. Note that not all neutron absorption by U-235 becomes
U-236; some U-235 atoms fission.
A neutron hits U 235 which then splits into a Cs 140 atom
(139.91728u), a Rb 93 atom (92.92204u), and several neutrons. How
many grams of U 235 do we need to start with to produce 1.3 x 10^9
J?
Q1)
What is the type of decay ( or nuclear decay reaction ) in diamond
??
Q2)
name just the steps of producing ethanol from Each of the a and
b
a)
from alcoholic fermentation ?
b)
from gasification or syngas ?
The half-life for the radioactive decay of U−238U−238 is 4.5
billion years and is independent of initial concentration.
Part A
How long will it take for 20% of the U−238 atoms in a sample of
U−238 to decay?
Express your answer using two significant figures.
Part B
If a sample of U−238 initially contained 1.1×1018
atoms when the universe was formed 13.8 billion years ago, how many
U−238 atoms will it contain today?
Express your answer using two significant figures.
1a Describe how thermal energy is obtained by
fission, specifically when a U=235 atom is hit by a slow-motion
neutron (less than 0.9 MeV). When one states that 200 MeV of energy
are released by a fission event, what is the form of this
energy?
1b. The energy released by fission is by the
change in mass and Einstein’s equation (E=Δmc2). If the
mass of one uranium 235 atom is 235.042924 amu and the mass of
fission products is 234.92754...
The following are
the P/E ratios, growth rates, beta and payout ratios of some firms
in the same industry
Company
P/E Ratio
Growth rate
Beta
Payout
BOE
17.3
3.50%
1.1
28%
GD
15.5
11.50%
1.25
40%
GMH
16.5
13.00%
0.85
41%
GRU
11.4
10.50%
0.8
37%
LK
10.2
9.50%
0.85
37%
LG
12.4
14.00%
0.85
11%
LR
13.3
16.50%
0.75
23%
MM
11
8.00%
0.85
22%
MD
22.6
13.00%
1.15
37%
NR
9.5
9.00%
1.05
47%
RY
12.1
9.50%
0.75...
illustrated a procedure to forecast the decay rates of isotopes
with known long average lifetimes. Lifetimes of the many U isotopes
vary from micoseconds to gigayears. F has only one stable isotope
while Sn has 10. Can Standard Model principles be used to predict
the stability of isotopes and the average lifetimes for unstable
isotopes, or can this only be done by measurement?