With these 4 questionssemester review section 1: measuring matter during this semester, you learned about an international system of units that scientists use to describe measurements of matter. this system is called the international system of units (si). 1. explain why this system was developed. 2. imagine you conducted a scienti? c experiment in the lab and you want another scientist to repeat it. if you used the standard si unit for mass, what unit would you be using? 3. what si unit would you use to describe temperature in this experiment? 4. if you write these directions for an experiment, why would someone else have a problem following them? "hold the chemicals 1.5 feet above the heat source." hint: you can ? nd the answers to this section's questions in lesson 3 of unit 1.