# The radioactive element thorium-234 has a half-life of approximately 24 days. If I started with 82 grams of it, how much thorium would remain after 96 days?

##### 1 Answer

Jun 5, 2018

#### Explanation:

If

#"n" = "96 days"/("24 days/half life") = "4 half lives"#

Amount of radioactive substance left after

#"N"_t = "N"_0/(2^"n")#

Where

#"N"_0 =# Initial Amount#"N"_t =# Amount left after#"n"# half lives#"n ="# Number of half lives