Thermal Energy (Heat, Temperature, and Pressure) Flashcards
Define temperature.
The average kinetic energy in the molecules or atoms of a substance.
List and describe the three types of thermal energy transfer.
- Conduction-direct touch/contact.
- Convection- transfer of heat through fluids, such as liquids or gases.
- Radiation- heat energy from light.
What is the specific heat capacity, (or just specific heat) of a material?
The amount of energy that it takes to increase a substance’s temperature by 1 degree.
If you place a beaker of water and an equally sized beaker of liquid mercury metal on the same hot plate, which substance will increase in temperature faster? Why?
The mercury. Because it is a metal, and has a higher thermal conductivity that water, meaning that heat flows through it easier.
Explain what happens to the temperature of ice as you continue to add thermal energy to it, all the way until it becomes steam. Drawing a graph may help you answer.
The temperature keeps increasing until it goes through a phase change. When it goes through a phase change, a lot of energy is added, but it’s temperature doesn’t change for a while.
How does a sweatshirt keep you warm?
It prevents convection. (And some conduction and radiation too.) It keeps your heat trapped next to you, so you stay warm.
During the day, warm air over the land rises, and is replaced by cooler air that comes from over the cool ocean. What type of thermal energy transfer is described here?
Convection. Heat flowing through fluids.
Give an example of a good thermal insulator.
Styrofoam, water, rubber, glass, air ( all of these have a low heat conductivity.)
20 grams of water are held in beaker “A” at 90 degrees Celsius. 10 grams of water are in beaker “B”, also at 90 degrees Celsius. How do the amounts of thermal energy in each glass compare?
Glass A has more thermal energy, since thermal energy is the total kinetic and potential of the molecules, and it has more volume, so more molecules.
You have a sealed balloon full of air that is at room temperature. What happens to the air inside as you warm it up, and how will the balloon’s shape or size change in response?
The air inside expands, or spreads further apart, causing the balloon to increase in size.
Why do scientists say that heat can be transferred from a warmer object to a colder object, but not the other way around?
Because heat transfer is always hot to cold. The “hot” molecules have more energy, therefore when they bump into the “cold” molecules, they lose energy and the “cold” ones gain energy or “heat up” because they gain speed from that energy.
