Astudent was conducting an experiment designed to study the law of conservation of mass. the student measured the mass of all the materials involved in the closed system reaction. the mass equaled 562g. what would we expect the mass to be after the reaction had occured?

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?