If a rock sample has a half-life of 10 years, and has 100 atoms of parent materi today, how many half-lives will have passed before it has only 25 atoms of parent material left Explain your reasoning

2

Explanation:

The half-life of a radioactive material is the time taken for a nuclide to decay to half its original composition.

Given:

 Half-life  = 10yrs

  Number of atoms in parent  = 100atoms

Unknown:

Number of half-lives what will pass for 25 atoms to remain:

                                     Start                         First half life     Second half life

Number of years           0                                    10                       20

Number of atoms          100                                 50                      25

The number of half-lives that will pass is 2

all fossil fuels are nonrenewable, so think coal, gasoline, things that we will eventually run out of. all fossil fuels are nonrenewable resources, but not all nonrenewable recourses are fossil fuels. these resources are not being renewed as fast as we are using them. i hope this considering there weren't any answer choices.