The half-life of a radioisotope is 30 days. What will remain a 20.0 sample after 90 days?

personal, she chose to do it.

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

the correct answer is:

a. formation of precipitation

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )