Question

The half-life of uranium-235 is 700 million years. If you start with 50 atoms of it, how many will you have left after 700 million years?
A. 50
B. 100
C. 25
D. 45

Answer 1

The answer is
A half life pertains to the time it takes for exactly half of a substance to disappear. So, if U235 has a half life of 700 million years, it will take 700 million years for half of it to decay. That would leave .5kg or 500g.

Answer 2

Answer:

A 50

i just guess for this answer but i don't really know if it right or not.