In the 1660s, Flemish physician Jan van Helmont grew a small

Last updated: 7/30/2022

In the 1660s, Flemish physician Jan van Helmont grew a small willow tree in a pot of soil. He added only water to the pot. At the end of five years, he found that the tree had gained 75 kilograms, but there was ver little change in the mass of the soil. Van Helmont concluded that the plant gained weight directly from the water. We now know that this conclusion is only partially correct because, in addition to water, photosynthes also requires (A) oxygen from the atmosphere (B) proteins from animal prey (C) carbon dioxide from the atmosphere (D) carbohydrates from the soil