In this unit, we will learn about heat – a form of energy that is generated by the movement of molecules in a substance. Even though we cannot see them, these tiny molecules are always moving, and the speed at which the molecules move determines the temperature of the object or substance.
We will also observe the three methods by which heat can be transferred – conduction, convection, and radiation. Through research and experimentation, we will compare these methods and see their effect on different types of materials.
Lesson 1: What is Heat? In lesson 1, we will examine the concept of heat. Essentially, heat is the transfer of thermal energy – a form of energy that comes from the movement of the molecules that make up an object or substance. All matter in the universe has some amount of thermal energy. The higher an object’s temperature, the more thermal energy it has. In a very warm material, molecules will vibrate or move very rapidly; however in a cooler material, molecules will move much more slowly. During this lesson, we will also see how temperature is used to measure the amount of thermal energy in an object. There are several different scales used to measure temperature, but we will be discussing the Fahrenheit, Celsius, and Kelvin scales. Download PDF Notes
Lesson 2: Methods of Heat Transfer Lesson 2, explores the methods by which heat can transfer between different objects or substances. We will be observing and comparing the three methods of heat transfer: conduction, convection, and radiation. Conduction is the transfer of thermal energy between two objects that are in contact with one another. In the case of convection, thermal energy is transferred by a current of gas or liquid. In the final method, radiation, thermal energy transfers through space by electromagnetic waves. In each of these cases, heat will always transfer from the warmer object to a cooler object. Eventually the warm object will become cooler and the cool object will become warmer until their temperatures are balanced. We call this point of balance thermal equilibrium. Over the course of this lesson, students will also be choosing one of the three methods of heat transfer to demonstrate to the class. Download PDF Notes
Lesson 3: Conductors and Insulators In lesson 3, we will be examining how heat can transfer differently through different materials. Some materials allow thermal energy to transfer to or from them easily. These materials are called conductors. Insulating materials, on the other hand, resist the transfer of thermal energy. Both conductors and insulators affect the ability of heat to transfer between objects and substances. We will look at several examples of conductors and insulators and will discuss the practical applications of these materials in our everyday lives. We will also be conducting experiments to determine which materials make the best conductors and insulators. Download PDF Notes
Lesson 4: The Effects of Heating and Cooling In lesson 4, we will see how changes in temperature affect different types of substances. As we have already discussed, changes in temperature affect the movement of molecules. As a substance’s temperature increases, its molecules move more quickly causing the substance to expand. On the other hand, a decrease in temperature causes a substance’s molecules to contract. These processes of thermal expansion and thermal contraction can have significant effects on many different substances, but they are particularly important to consider in construction and engineering projects. Additionally, we will explore how significant changes in temperature can even change the physical state of substances. Download PDF Notes
Resources and Other Documentation
Unit 4 Guided Notes The guided notes for each unit provide students with a printable copy of notes summarizing the content from each class. Blanks are inserted into the notes where key facts or content should appear. As information is covered during class, students should write missing content into the blanks to complete the guided notes. These guided notes may also be used as a review tool for unit tests. Students may print a copy of the guided notes and fill in the missing content. This can be checked using the complete PDF notes for each lesson.