Pre Calculus
posted by Brianna
If a 25 mg sample of radioactive material decays to 18.4 mg in 5 years, how long will it take the sample to decay to 20.5 mg?
Respond to this Question
Similar Questions

CalculusModeling Equations
An unknown radioactive element decays into nonradioactive substances. In 420 days the radioactivity of a sample decreases by 39 percent. 1.What is the halflife of the element? 
calculus
Carbon14 is a radioactive substance produced in the Earth's atmosphere and then absorbed by plants and animals on the surface of the earth. It has a halflife (the time it takes for half the amount of a sample to decay) of approximately … 
chemistry
How long will it take for 25% of the C14 atoms in a sample of C14 to decay? 
Pre Calculus
Exponential Growth and Decay Find the halflife of a radioactive substance that decays by 5% in 9 years. 
calculus
The rate at which an amount of a radioactive substance decays is modeled by the differential equation dA/dt = kA, where A is the mass in grams, t is the time in years, and k is a constant. Answer the following. a) If a 100gram sample … 
math
An unknown radioactive element decays into nonradioactive substances. In 100 days the radioactivity of a sample decreases by 64 percent. a)(a) What is the halflife of the element? 
Science Radioactive Dating
Which of the following statements about radioactive dating is true? 
SCIENCE
We did a radioactive decay and half life lab with m&ms and I do not understand these conclusion questions: 1. how many half lives would it take for 500 nuclei to decay to 6.25% of the original number of nuclei? 
pre calc
A 50 gram sample of radioactive strontium will decay to 32 grams in 18 years. a. Find an equation that will model how much of our sample M will remain after t years. 
Engineering Math
An unknown radioactive element decays into nonradioactive substances. In 120 days the radioactivity of a sample decreases by 59 percent. What is the half life of the element?