Chemistry Homework Help

24/7 Chemistry Homework Help

Get step-by-step solutions from expert tutors.

How it works?

Ask a question

Type, take a picture, or paste your question with all necessary details to ensure high-quality responses.

Get an answer in less than 24hrs

Once our tutors receive the question, they'll begin. You'll get an email once the solution is ready.

Get Notified

We will send you email and text notification to let you know when your question is answered.

Browse Homework Solutions

84 solutions

First Order Half Life

Q. Consider the decay series A → B → C → D in which A, B, and C are radioactive isotopes with half-lives of 4.50 seconds, 15.0 days, and 1.00 seconds, respectively, and D is nonradioactive. Starting with 0.86 mole of A, and none of B, C, or D, calculate the number of moles of A, B, C, and D left after 30 days.

Solved • Dec 15, 2019

First Order Half Life

Q. The activity of a radioisotope is 3000 counts per minute at one time and 2736 counts per minute 48 hours later. What is the half-life, in hours of the radioisotope?

Solved • Dec 13, 2019

First Order Half Life

Q. After 55 years, what mass (in g) remains of a 200.0 g sample of a radioactive isotope with a half-life of 10.0 g years

Solved • Dec 13, 2019

First Order Half Life

Q. A certain substance follows a first-order decomposition. It is found that 50% of the original substance decomposed after 8.75 hours. (a) How much additional time will it take for 99.9% of the initial substance to have decomposed? (b) How much time is required for the extent of the decomposition to go from 99.9% to 99.99%?

Solved • Dec 11, 2019

First Order Half Life

Q. The Cs-131 nuclide has a half-life of 30 years. After 107 years, about 3.0 grams remain. The original mass of the Cs-131 sample is closest to

Solved • Dec 11, 2019

First Order Half Life

Q. The half-life of 90-Sr is 28 years. How long will it take for a given sample of 90-Sr to be 64% decomposed?

Solved • Dec 11, 2019

First Order Half Life

Q. Consider a certain type of nucleus that has a half-life of 32 min. Calculate the percent of original sample of nuclide remaining after 1.9 hours have passed.

Solved • Dec 11, 2019