Can be a number of things, rain fall quota, climate, population, vegetation..any of those.
Answer:
grams
Explanation:
Given -
Half life of the silicon-32
years
Half life means the time period required by a radioactive element to reduce its mass by half.
Radioactive decay formula is

Where
A represents the amount of radioactive element after time t years
represents the initial amount of radioactive element
time of decay
half-life of the substance
Substituting the given values in above equation, we get -

grams