The half-life for the radioactive decay of U-238 is 4.5 billion years and is independent of initial concentration. Part A How long will it take for 10% of the U-238 atoms in a sample of U-238 to decay? Express your answer using two significant figures. 190 ΑΣΦ Α 0.638 Submit Part B Previous Answers Request Answer * Incorrect; Try Again; 4 attempts remaining ? 16] ΑΣΦ N- 1.88 10° If a sample of U-238 initially contained 1.4x10¹8 atoms when the universe was formed 13.8 billion years many U-238 atoms will it contain today? Express your answer using two significant figures. Submit Previous Answers Request Answer ут X Incorrect; Try Again: 3 attempts remaining atoms

Cor • Part A The half-life for the radioactive decay of U – 238 is 4.5 billion years and is independent of initial concentration. How long will it take for 16 % of the U – 238 atoms in a sample of U – 238 to decay? Express your answer using two significant figures. Templates Symbols ugdo redo reset keyboard shortcuts help t = уг Submit Request Answer Part B If a sample of U – 238 initially contained 1.3x101° atoms and was formed 6.1 billion years ago, how many U – 238 atoms does it contain today? Express your answer using two significant figures. Templaes Symbols uado redo rest keyboard shortcuts help, N = atoms

strontium-8 is a readioactive maker used in scanning for bone disease including cancer that decays by a first order process with a half-life of 78.3 hours. if a study start with 1.50*10^-2 mol of stronitum-81, how much is left after 168 hours?

The 1st-order decay of a particular radioactive element has a half-life of 1.234 days. How many grams of radon remain after 5.67 days if the sample initially weighs 891.0 grams? Group of answer choices 307 508 36.9 0.815 76.3

What is the half-life (in y) of a radioisotope if it decays to 25% of its radioactivity in 13.5 years? (Enter an unrounded answer.)

The half life for the radioactive decay of carbon-14 to nitrogen-14 is 5.73x 10^3 years. Suppose nuclear chemical analysis shows that there is 0.888 mmol of nitrogen-14 for every 1.000 mmol of carbon-14 in a certain sample of rock. Calculate the age of the rock. Round your answer to 2 significant digits.

2) Two lakes are connected to each other as shown in the figure below. Each lake has a volume of 106 m³ and an initial concentration of 10 g/m³. Lake 1 receives an inflow of 105 m³/day and a concentration of 100 g/m³. In addition to the Lake 1 outflow, Lake 2 receives an inflow of 1x105 m³/day with a concentration of 100 g/m³. The chemical undergoes first-order decay with a rate constant of 0.1 /day. (i) Calculate the steady-state concentrations (in g/m³) in the effluent from the lakes. (Include the mass balance equations in your solution.)

A certain drug has a half-life in the body of 5.0 h. What should the interval between doses be, if the concentration of drug in the body should not fall below 25.% of its initial concentration? Round your answer to 2 significant digits. h

The half life for the radioactive decay of potassium-40 to argon-40 is 1.26× 10⁹ years. Suppose nuclear chemical analysis shows that there is 0.723 mmol of argon-40 for every 1.000 mmol of potassium-40 in a certain sample of rock. Calculate the age of the rock. Round your answer to 2 significant digits. years x10 X

The half life for the radioactive decay of carbon-14 to nitrogen-14 is 5.73 x 10° years. Suppose nuclear chemical analysis shows that there is 0.276 mmol of nitrogen-14 for every 1.000 mmol of carbon-14 in a certain sample of rock. Calculate the age of the rock. 圖 Round your answer to 2 significant digits. alo years Explanation Check O 2022 McGraw Hill LLC. All Rights Reserved. Terms of Use I Privacy Center| Accessibility IA (99+