Strontium-85 has a half-life of 65 days. how long will it take for the radiation level of strontium-85 to drop to one-fourth of its original level?

130 days

Explanation:

Strontium-85 has a half-life of 65 days. how long will it take for the radiation level of strontium-85 to drop to one-fourth of its original level?

Strontium-85 is a radioactive element. so it takes 65days for one strontium of a particular mass to decrease to half of its initial size

Half life  is the time taken for a radioactive element to decrease to half of its initial size. it decays by half every 65 days.

from 1 to 1/2  = 65 days

from 1/2 to 1/4  =65 days

from 1/4 to 1/8 = 65 days

from 1/8 to 1/16 = 65 days

total time taken to decay from original amount to 1/4 is two half lives =

65+65=130 days

first thing first of the answer is with technology. second thing second thing is that the big bang theory did not happened u see they say it did but what they dont realize is that like dinasures are still a round they might deny it but they and look at these 12 foot human skelteons they find lets see didnt the bible say something about giants. hope this peace.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide