If the half life of uranium-232 is 70 years, how many half lives will it take for 10 g of it to be reduced to 1.25g

Very hard to understand

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.

Your answer is a because that is true