Thermal Energy

Master thermal energy! This worksheet explains heat, temperature, and energy transfer for 7th graders.

Use this worksheet to learn about the differences between heat and temperature. Science of Heat Heat is the transfer of energy from one object to another due to a difference in temperature. Heat can be measured in joules, BTUs (British thermal unit) or calories.Heat and temperature are closely related, but they are not the same thing. The temperature of an object is determined by how fast its molecules are moving. The faster the molecules are moving the higher the temperature. We say objects that have a high temperature are hot and objects with a low temperature are cold. Heat is the transfer of _ from one object to another due to a difference in temperature. time energy force velocity current Which of the following is a unit of measurement for heat? Calorie BTU Joule All of the above None of the above True or False: Heat and temperature are the same thing. True False What happens to the molecules of a substance as it gets cooler? The molecules shrink. They molecules expand. The molecules move faster. The molecules move slower. Nothing. Transferring of Heat When two items are combined or touching each other, their molecules will transfer energy called heat. They will try to come to a point where they both have the same temperature. This is called equilibrium. Heat will flow from the hotter object to the colder. The molecules in the hotter object will slow down and the molecules in the colder object will speed up. Eventually they will get to the point where they have the same temperature.This happens all the time around you. For example, when you take an ice cube and put it into warm soda. The ice cube will become warmer and melt, while the soda will cool down. What is it called when two objects touching each other eventually reach the same temperature? Expansion Conduction Equilibrium All of the above None of the above Hot Objects Expand When something gets hotter it will expand, or get bigger. At the same time, when something gets cold it will shrink. This property is used to make mercury thermometers. The line in the thermometer is actually liquid mercury. As the liquid gets hotter, it will expand and rise in the thermometer to show a higher temperature. It's the expansion and contraction due to temperature that allows the thermometer to work. Do substances tend to shrink or expand as they get hotter? They shrink. They expand. They stay the same. Heat Conduction When heat transfer from one object to another, this is called conduction. Some materials conduct heat better than others. Metal, for example, is a good conductor of heat. We use metal in pots and pans to cook because it will move heat from the flame to our food quickly. Cloth, like a blanket, isn't a good conductor of heat. Because it's not a good conductor, a blanket works well to keep us warm at night as it won't conduct the heat from our bodies out to the cold air. What is the called when heat transfers from one object to another? Induction Expansion Expansion Equilibrium Deduction Conduction Which of the following is not a good conductor of heat? A steel pan Copper wire A blanket An iron rod Metal Matter Changing State Heat has an impact on the state of matter. Matter can change state based on heat or temperature. There are three states that matter can take depending on its temperature: solid, liquid, and gas. For example, if water is cold and its molecules are moving very slow, it will be a solid (ice). If it warms up some, the ice will melt and water becomes a liquid. If you add a lot of heat to water, the molecules will move very fast and it will be come a gas (steam). In what state of matter is the temperature the highest? Solid Liquid Gas The temperature doesn't matter In what state of matter is the temperature of water the lowest? Solid Liquid Gas The temperature doesn't matter