: Science Quiz On Heat Flow Across Materials, Science Quiz For Kids Online, 1st, 2nd & 3rd Grades. In this quiz students will learn about heat flow. Usually, the principle is that heat flows from places that are relatively hotter to others that are cooler. In this quiz, students are presented with diagrams showing different temperatures at different points in an object. There are arrows suggesting the potential path of heat flow. Students have to study the diagram and determine the possible direction heat will follow. This is a science activity that can be experimented in a lab. Review some science facts and improve your understanding of heat flow. Click start to begin.