Three important resources include energy, mineral, and timber.
Energy (natural gas, crude oil, crude bitumen (oil sands) and coal)
Mineral (gold-silver, nickel-copper, copper-zinc, lead-zinc, iron, molybdenum, uranium, potash and diamonds)
Natural resources are important for supporting the economy, and supporting the necessity of the citizens.
Good luck on your assignment!
Answer:
mountain chains, earthquakes, volcanoes.
Ok so the answer will be C
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.