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:
Antarctica
Explanation:
the ice melts because of global warming
This is the only one I know
What is the dominant language of sub-Saharan Africa?
<span>Three of the six dominant languages in Subsaharan Africa—spoken by at least ten million people or more—are spoken in Nigeria: Hausa, Yoruba, and Ibo. The three remaining major languages of Subsaharan Africa are Swahili, Lingala, and Zulu.</span>
Answer:
Stalactites hang from the ceiling of a cave while stalagmites grow from the cave floor. ... A stalactite is an icicle-shaped formation that hangs from the ceiling of a cave and is produced by precipitation of minerals from water dripping through the cave ceiling. Most stalactites have pointed tips.
The drawing of the boundaries in the manner of the interest of the European colonial powers resulted in very big problems once the African countries were granted independence.
The problems were mostly because people from the same ethnic groups were separated by borders, but were in the same ones with people from other ethnic groups, usually historical rivals with whom they had bad relations. Also, the religious factor had a big influence, as there were multiple countries were some parts were predominantly of one religion, and other parts of other religion, and that brought in even more tensions.
That has resulted in instability, constant tensions, civil wars, terrorist organizations, separatist movements, genocides, pretty much everything that is not supposed to happen for a country to prosper.