You have just isolated a new radioactive element. if you can determine its half-life, you will win the nobel prize in physics. you purify a sample of 2 grams. one of your colleagues steals half of it, and four days later you find that 0.3 gram of the radioactive material is still left. what is the half-life? (round your answer to three significant digits.)

Staals half
1 gram left
0.3 grams left
half lives are normally written in years
it goes likt this


A=final amount
P=initila amount
t=time elapsed
h=time half life is (same units as time)

let's use days as the units of time

we are given
initial amount=1gram
final amount=0.3gram
time=4 days

so

solve for h

take the ln of both sides


times both sides by h

divide both sides by ln(0.3)

use calculator
h=2.30287
3 sig figs
h=2.303 days

Agc and bgd are vertical angles