The radioactive substance cesium-137 has a half-life of 30 years. the amount at (in grams) of a sample of cesium-137 remaining after t years is given by the following exponential function.
at(t)=458(1/2)^(t/30)
find the amount of the sample remaining after 20 years and after 50 years. round your answers to the nearest gram as necessary.

The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g

Explanation:

We are given a function that calculates the amount of sample remaining after 't' years, which is:

Putting values in above equation:

Hence, the amount of sample left after 20 years is 288.522 g

Putting values in above equation:

Hence, the amount of sample left after 50 years is 144.26 g

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be