Answer:

Explanation:
plug in the radius for r and the v doesn't matter
Answer:
1.5*10^24
Explanation:
1 mol of any substance contains 6.02*10^23 particles of this substance.
2.5*6.02*10^23 =1.5*10^24
You need to use a conversion factor of 1000mm to 1 m. So divide by 1000. Then you should have 4 digits total by the significant figure rules since the number in the problem is 4 digits.
Based on my information, this would be known to be a "green house" as this, would be as it would be a house known for planting, and etc. But the main part that I wanted to consider would be the fact that it would also be a "closed system" as you would be able to open and close this kind of machine.
Your answer: a greenhouse