Question 4 of 20
4 Points
A radioactive element has a half-life of 3,000 years. If a sample of this
element begins with a mass of 60 grams, how long would you have to wait for
the mass to decrease to 15 grams?
O
A. 6,000 years
O
B. 12,000 years
O
O
C. 3,000 years
D. 1,500 years
BH

A. 6,000 years

Explanation:

Original sample N = 60 g

The half life of N/2 is 3000yrs

N/4 is 6000yrs

N/4 ===> 15 gram

it takes 6000yrs to decrease to 15grams

since there isn't any suggested answers i will give you the reason and hopefully you can figure it

south africa, or rather all of africa, has not been in the location in which it is nowadays throughout the geological past. after the super-continent pangaea started to break apart, gondwanaland, in which was africa, moved further south, and parts of it came to be very close to the south pole. because the climate in this part of the world is very cold due to the very dispersed sun rays in there, what is now south africa, started to freeze, and the conditions were right for the formation of glaciers. the glaciers existed up until the period when gondwanaland started to break apart and what is now africa started to move towards north, sp it warmed up and the glaciers melted.