Atmospheric gasses that absorb infrared radiation
Answer:
They release Carbon Dioxide (CO 2)
Set this up as
10 = 40 (1/2)t/28
and solve for t in years.
10/40 = (1/2)t/28
log(0.25) = (t/28) log(0.5)
t = 28 log(0.25) / log(0.5) years = 56 years
Test the answer:
56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.
Answer:
Oil, natural gas, and petroleum products dominate the second group, while linseed oil, cotton, cattle hides, fish meal, wool, copper, tin, iron ore, lead, and zinc top the third group. South American manufactured goods have gained access to world markets as well.