The half-lives of 235U and 238U are 7.04 × 10° years and 4.47 × 10° years, respectively, and the present abundance ratio is 238U/235U = 137.7. It is thought that their abun- dance ratio was 1 at some time before our earth and solar system were formed about 4.5 × 10° years ago. Estimate how long ago the supernova occurred that supposedly produced all the uranium isotopes in equal abundance, including the two longest lived isotopes, 238U and 235U. Using the result of problem 29 and the accepted age of the earth, 4.5 x 10° yr, calculate the 238U/235U ratio at the time the earth was formed.

Q: An unknown element is found to have three naturally occurring isotopes with atomic masses of 35.9675…

A: Given that x1 =0.337 x 10-2M1 =35.9675x2 =0.063 x 10-2M2 =37.9627x3 =96.6 x 10-2M3 =39.9624

Q: Hw: 1 what is the half-life of a substance that decays to 25% of its original amount in 6 days ?

A: A radioactive substance decays by first-order kinetics. If mo is the initial amount of the…

Q: Calculate the work done by a sample of nitrogen that expends reversibly and adiabatically from…

A: Given data: V1 = 1 dm3 V2 = 3.6 dm3 P1= 57.4 kPa γ = 1.4

Q: Use the following information to fill in the blanks below. Upon combustion, a 10.582 g sample of a…

A: Sample Weight = 10.582 g CO = 226.9760 g H2O = 6.8940 g

Q: The volume of a binary mixture in cm3 mol-1 can be predicted using the expression below: V = 65x1 +…

A: Molar volume of a binary mixture is given. Molar composition of the mixture is, x1 = 0.47 x2 = 0.53

Q: A sample of nitrogen at 23°C is allowed to expand reversibly and adiabatically from 400 cm³ to 3600…

A:

Q: Example 8.4-6 Equipment Encyclopedia heat exchanger www.wiley.com/college/felder Solution Material…

A: To locate any point on psychometric chart any two point is needed.It can be…

Q: Examine the odd numbered elements. For example step through the odd numbered elements between atomic…

A: Answers to above statements are given below:

Q: The decay of U-238 to Pb-206 can be used to estimate the age of inorganic matter. The half-life of…

A: The decay of the U - 238  to Pb - 206 is used to estimate the age of the inorganic matter .The half…

Q: In the laboratory, you are studying the first-order conversion of a' reactant X to products in a…

A: The given reaction is of first order:In the first order reaction the concentration of the reactant A…

Q: For a binary mixture of components 1 and 2, the molar enthalpy of the mixture (J/mol in terms) are…

A:

Q: Hot water volume ,V1 = 100 mL Hot water initial temperature, T1 = 43. 0°c Final water volume, V2 =…

A: In thermodynamics, the melt is a simple physical process in where phase changes of the water in the…

Q: 8.278 x 104 mol of an unidentified gaseous substance effuses through a tiny hole in 86.9 s Under…

A:

Q: Components A and B are in vapor-liquid equilibrium. Initially, 1 mole of liquid (?? = 0.4) and 0.1…

A: Given: Components A and B are in vapor-liquid equilibrium. Initially, 1 mole of liquid (?? = 0.4)…