Provide a process for solving half-life problems. Example: An isotope of cesium (cesium-137 has a half -life of 30 years. If 1.0 mg of cesium-137 disintegrates over a period of 90 years, how many mg of cesium-137 would remain?
Carbon-14 datin of ancient objects requires that material to be organic in order to assay its age. You hear someone sat that a dinosaur bone ws carbon dated to be 75 million yaers old. What are two specific reasons that this claim is incorrect?
10. The amount of radioactive material, in grams, present after t days is modeled by (see equation in attached file) a) What is the initial amount of material? b) How much material is left after 10 days? c) Find the half-life of the material.
The muon is a subatomic particle with the same charge as an electron but with a mass that is 207 times greater. m_u = 207m_e. Physicists think of muons as "heavy electrons". However, the muon is not a stable particle; it decays with a half-life of 1.5 microseconds into an electron plus two neutrinos. Muons from cosmic rays are s
1. (A) Efforts are underway to produce energy commerically by fusion. It is too difficult to produce helium by fusion of protons, as is done in the sun, so we have to start with heavier nuclei such as deuterons. One possible reaction is Calculate the energy, in MeV, released in this reaction. (4.032 MeV) The abundance of de
1. An electron drops from the L shell to the K shell and gives off an X-ray with a wavelength of 0.0205 nm. What is the atomic number of this atom? Answer 78 2. A radioactive substance has a decay constant equal to 8.9x10^-3s-1. What is the half-life of this substance? Answer 78sec 3. How many rad of 200-keV X-rays caus
226-88 Ra, a common isotope of radium, has a half-life of 1620 years. Knowing this, calculate the first order rate constant for the decay of radium-226 and the fraction of a sample of this isotope remaining after 100 years.
Cobalt-60 is used in radiotherapy; a 100 GBq source is delivered to a hospital on 1/1/1999; i. How many gamma rays will the source produce in a 15 second treatment period? ii. if the half-life of cobalt-60 is 5.27 years, what is the activity of the source on 1/9/2004? iii. If a treatment took 15 seconds on 1/1/1999 how long w
11. The half-life of a first-order reaction is 13 min. If the initial concentration of reactant is 0.085 M, it takes _____ min for it to decrease to 0.055 M. a. 8.2 b. 11 c. 3.6 d. 0.048 e. 8.4 12. The mechanism for formation of the product X is:
If one gram of Carbon 14 nuclides from an old bone is found to give off 0.478 decays (energy units) per minute, how old is this sample if originally the carbon-14 sample gives off 7.65 decays per minute, and the half life is 5715 years?
What determines whether a particular element will have alpha or beta decay? For example 238 4 234 U -----> He + Th 92 2 90 is always shown as having alpha decay in books Is this always the case? Why does it not have beta decay? Is one
Question 84 (a) A circular conducting loop carries a current of 5.0 A and has radius 30 mm (i) Calculate the magnetic field at the centre of the loop (H) How many turns would be needed to give a field of 1.0 mT (b) A electron is injected into the 1.0 mT magnetic field mentioned in part (a) with a velocity of 2500 m S-lin a
The naturally occurring isotopes of Potassium are: 39 K (abundance 93.10%) 40 K (abundance 0.0118%) 41 K (abundance 6.88%) d) What percentage of 40 K nuclei will decay in the next 10,000 years? f) Using the definitions for the decay constant and for the becquerel, calculate the activity of 1 gram of naturally occurrin
Question: A hospital physicist measure the strength of a cobalt - 60 X-Ray machine every year. His result over a six year period are shown in the table. Strength is measured in MBq (megabecquerels) or millions of counts per second. Strength (MBq) C 10.0 8.8 7.8 6.9 6.1 5.4 4.8 Time t (years)
Half-Life of a Reaction. Consider the following reaction at 300 C: NO2(g) = NO(g) + 1/2 O2(g). a. Describe what kinds of plots you would have to construct to determine if the reaction is first-order or second-order. b. What would these plots look like and how would they allow you to determine the order of the reaction
Radioactice substances decay exponentially. The amount of radium present at an time t obeys the law Q(t)= Qoe^-kt, where Qo. is the initial amount present and k is a suitable positive constant. The half-life of a radioactive substance is the time required for a given amount to be reduced by one-half. Now, it is known that the ha
At 300 K the reaction below obeys the rate law Rate=k[NOCl]^2, where k=2.8 X .000010 M to the neg 1 times s to the neg 1. 2 NOCl >>>>>> 2NO + Cl2 Suppose 1.0 mole of NOCl is introduced into a 2.0-liter container at 300 K. Evaluate the half-life of the reaction.
The second order reaction for the decomposition of nitrosyl bromide has a half life of 12.5s at a concentration of 0.100M. NOBr(g)-->NO(g) + 1/2Br2(g) I need help finding k for the reaction, and how would I find how long it will take to decompose 80 % of a 0.0500M solution of nitrosyl bromide, and how fast 0.200M solutio
a) Tritium (H-3) has a radiological half-life of 12.3 years. What is its specific activity in units of Bq/g and Ci/g? b) A 0.2 gram sample of Kr-85 gas, which decays into stable Rb-85, is accidentally broken and escapes into a sealed warehouse measuring 40 x 30 x 20 m. What is the specific activity of the air inside in Bq/cm^
A very old specimen of wood contains 10^12 atoms of carbon: a) How many C-14 atoms did it contain in the year of 9474 B.C.? b) How many C-14 atoms did it contain in 2004 A.D.?
Email me for Clarification. I only need Parts C and D... I solved A and B, the answers are below. Not too much work left for 25 credits. Your help is appreciated. The only radiogenic lead isotope that is not either stable (Pb-206, 207, 208) or with a halflife of less than one day is Pb-210, which is found in nature in sec
1. Calculate the radius of curvature of the path of a beta particle of mass 9.1 x 10^-31 kg and speed 2.0 x 10^7 m/sec perpendicular to a magnetic field of 0.50 T. a. 0.23 mm b. .46 mm c. 0.92 mm d. 0.051 mm 2. Calculate the radius of curvature of the path of an alpha particle of mass 6.6 x 10^-27 kg mov
At standard Temperature and pressure sound travels at speed u=330m/s relative to the air through which it propagates. Four students A,B,C and D position themselves as shown if figure 1.20 (see attachment), with A,B,C in a straight line and D vertically above B. A steady wind is blowing with speed 30m/s along the line ABC. If
Question: 32P has a half life of 14.26 days. If you start with 200.0 g of it, how many grams will remain after a time of 3(14.26) days?
A threory of nuclear astrophysics is that all the heavy elements like uranium are formed in supernova explosions of massive stars, which immediately release the elements into space. If we assume that at the time of the explosion there were equal amounts of 235U and 238U, how long ago were the elements that formed our Earth rele
A 10.0 g sample of uranium-27 (u-237) undergoes beta decayy. After 27.0 d, 0.625 g of U-237 remains. Calculate the half-life of u-237. Please show me each step in the calculations. Thanks.
Find the half-life of a radioactive material if, after one year 99.5713% of the amount remains, also write the formula for finding the amount of this material after (t) years, and how much will remain in 500 years?
The age of a piece of wood from an ancient source is determined by carbon dating. The carbon-14 content of a sample of the wood is found to be one-fourth that of living trees. The half life of carbon-14 is 5730 years. How old is the piece of wood?
Select the three options which are NOT examples of quantities that could be modeled by exponential growth or decay. Options A. The number of students registering for named degress at the Open University, if each year there are 5% more than the previous year. B. The world's reserve of a certain mineral, given that 1000
A 1.00g of sample of Ge decays to 0.87 in 1.9hr. What is the half-life of Ge? Please show how you arrive at the solution. thanks a. 1.4 x 10(exponent 1)hr b. 9.5 hr c. 1.1 x 10(exponent negative 1) hr d. 7.3 x 10(exponent negative 2) hr e. 13 hr