Question

A 320.3ng sample of an unknown radioactive substance was placed in storage and its mass measured...

A 320.3ng sample of an unknown radioactive substance was placed in storage and its mass measured periodically. After 47 days the amount of radioactive substance decreased to 40.04ng. How many Half lives of the unknown radioactive substance have occurred?

Science   Chemistry   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Initially 100 milligrams of a radioactive substance was present. After 5 hours the mass had decreased...
Initially 100 milligrams of a radioactive substance was present. After 5 hours the mass had decreased by 7%. If the rate of decay is proportional to the amount of substance present at time t, determine the half-life of the radioactive substance
Initially 100 milligrams of a radioactive substance was present. After 8 hours the mass had decreased...
Initially 100 milligrams of a radioactive substance was present. After 8 hours the mass had decreased by 4%. If the rate of decay is proportional to the amount of the substance present at time t, determine the half-life of the radioactive substance. (Round your answer to one decimal place.)
1. Suppose that you are given a 200 gram sample of a radioactive substance with a...
1. Suppose that you are given a 200 gram sample of a radioactive substance with a half-life of 45 days. How many grams will be left after 360 days? 2. A radioactive substance is found to register 5000 counts per second on a Geiger counter. Twenty-four hours later it registers 1250 counts per second. What is its half-life? 3. If a sample emits 2000 counts per second when the detector is 1 meter from the sample, how many counts per...
i recieved 50 grams of an unknown radioactive isotope. 30 days after recieving it there are...
i recieved 50 grams of an unknown radioactive isotope. 30 days after recieving it there are 25 grams left. Identify the half life of the substance and calculate how many days from initially recieving the isotope until there will only be 10 grams left
An unknown radioactive element decays into non-radioactive substances. In 860 days the radioactivity of a sample...
An unknown radioactive element decays into non-radioactive substances. In 860 days the radioactivity of a sample decreases by 54 percent. (a) What is the half-life of the element? half-life: (days) (b) How long will it take for a sample of 100 mg to decay to 91 mg? time needed: (days)
An unknown radioactive element decays into non-radioactive substances. In 860 days the radioactivity of a sample...
An unknown radioactive element decays into non-radioactive substances. In 860 days the radioactivity of a sample decreases by 49 percent. (a) What is the half-life of the element? half-life:   (days) b) How long will it take for a sample of 100 mg to decay to 78 mg? time needed:  (days)
ple 1: The mass of a radioactive substance follows a continuous exponential decay model, with a...
ple 1: The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate parameter of 8.5% per day. Find the half - life of this substance (that is, the time it take for one - half of the original amount in a give sample of this substance to deca
An unknown radioactive element decays into non-radioactive substances. In 520 days the radioactivity of a sample...
An unknown radioactive element decays into non-radioactive substances. In 520 days the radioactivity of a sample decreases by 35 percent. (a) What is the half-life of the element? (days) (b) How long will it take for a sample of 100 mg to decay to 44 mg? time needed: (days)
An unknown radioactive element decays into non-radioactive substances. In 640 days the radioactivity of a sample...
An unknown radioactive element decays into non-radioactive substances. In 640 days the radioactivity of a sample decreases by 50 percent. What is the half-life of the element? How long will it take for a sample of 100 mg to decay to 70 mg?
Part A You are using a Geiger counter to measure the activity of a radioactive substance...
Part A You are using a Geiger counter to measure the activity of a radioactive substance over the course of several minutes. If the reading of 400. counts has diminished to 100. counts after 78.4 minutes , what is the half-life of this substance? Express your answer with the appropriate units. Part B An unknown radioactive substance has a half-life of 3.20 hours . If 26.8 g of the substance is currently present, what mass A0 was present 8.00 hours...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT