Astandard major league baseball has a mass of about 150 grams. an aspirin has a mass of about 300 milligrams. how many asprins would have about the same mass as one baseball?

There are 1,000 milligrams in 1 gram, so...
Let's divide

300 milligrams = 0.3 grams
Now...

500 aspirins would have about the same mass as one baseball

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.