Answer:
5
Explanation:
just subtract 20-25 and 5 is left over which is how much the water when up with the rock.
Answer: polyatomic
Explanation:hope you find helpful
1 mol ---- 40g
X --------- 15g
X = 15/40 = 0,375 moles
:)
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
