If you start with a 10g chunk of 235 Uranium how much Uranium will be left after 713 million years?

5g will be left

Explanation:

Uranium 235 have a half-life of 700 million* years. This means that the element will decay to half its initial amount by that time. So if I start with 10g chunk of 235 Uranium, after 713 million years, only half of it (5g) will be remaining.

*the exact half life of Uranium 235 is 703,800,000 years.

b. 20: 5

explanation:

20% of the worlds population lives in southwest asia, and less than 5% of the world's

land area.

the answer would be the third option, "no, ariel should have added 9^2 and 12^2 and compared that to 15^2."

this is found through the pythagorean theorem, which is a^2 + b^2 = c^2.

this is the correct way of solving the problem:

9^2 + 12^2 = 15^2

81 + 144 = 225

225 = 225