Heat and Temperature for grade 7 learners .pptx

explains about heat and temperature

1. Heat and Temperature Grade 7

2. Topic 1: Using Energy From Heat We use heat to cook our food and keep us warm, however if heat is uncontrolled it can be dangerous. The many uses of heat energy include: Hair styling tools, washing and drying clothes, electric kettles to boil water, electric stoves, microwaves etc… As people's lives change, their needs and wants, we learn and invent new technologies to make life easier or more convenient. This is where understanding science can really help! If you know how heat energy and heat transfer work you can not only make safer choices but you can invent new things!

3. Topic 2- Measuring Temperature You probably think of temperature of the number that tells you how hot or how cold something is. In this unit we will dive into a more scientific definition and understanding of what temperature is. There are many ways we can estimate the temperature of something, we can touch it(nurse or a doctor feeling the forehead), look at the color of it emits ( a flame of a welder or glass blower or stars in the night sky). Estimating Temperatures can not always be safe by using our sense so we had to think of other ways!

4. Thermometers Scales are important! We use clusius ! We need to use the right tool for the right job. Thermocouples (two different intertwined metals used to measure extremely high temperatures) Bimetallic Strips (Two metals one that expands faster when heated are placed on top of one another to form an expanding and contracting coil) The Recording Thermometer (The bimetallic strip with the pen on the drum, measures temperature over a seven day period) The Infrared Thermogram (A camera which allows you to see radiation or heat in colors)

5. The particle Model, Temperature and Thermal Energy

6. Topic 3 - The Particle Model, Temperature, and Thermal Energy The particle model of matter is a scientific description of many different features of these tiny particles. Three of the most important ideas of the model are: All substances are made of tiny particles too small to be seen The particles are always in motion - vibrating, rotating and moving from place to place. The particles have spaces between them

7. Matter Matter’s Assignment Have Fun!

8. Temperature and the Particle Model When the motions of a particle change in a substance so does the temperature When a substance warms the particles are moving faster When a substance cools it’s particles are moving slowly This idea forms the fourth point in the particle model: The motion of the particles increases when the temperature increases. The motion of the particles decreases when the temperature decreases. Energy is the measure of something's ability to do work or to cause changes.

9. Thermal Energy Hot-air balloons, ovens, a hot tub- these and many other devices are designed to release and transfer thermal energy (energy associated with hot objects). The fuel in a hot-air balloon burns transferring thermal energy to air, which warms, expands, and lifts the balloon. Hot metal elements in a oven transfer thermal energy to food, warming and cooking it. Hot water transfers thermal energy to people in the tub.

10. Topic 4- Expansion and Contraction Substances expand when heated and contract when cooled The same is true with solds, when they are heated they expand and when they are cooled, they contract Gasses are difficult to observe but again, when they are heated they expand and when they are cooled, they contract As we discussed with liquids, the same is true. We know this because the liquid in a thermometer moves up the device when heated because the heat makes the liquids expand and of course the liquid falls when it’s cooled because when it is cooled, it contracts

11. Topic 5- Changes of State

12. Topic 1-5 Quiz

13. Demo Day! Because you worked hard- You earned a day to sit back, relax, enjoy and of course learn! Today is a bangs, flashes and fire day! Take out your cameras you;re about the be amazed Today you will see The gummy bear sacrifice … yikes El-flamo! Oooo ahhhh Elephant's Toothpaste!

14. Quiz Review topic 1-5 https://docs.google.com/document/d/1gKR94jp4EprmbYcQSR5G20B8EFSLRee-R9s3ef-Y3Hg/edit

15. Topic 6 - Transferring Energy When you hold your hand in front of a light bulb you have felt heat- The heat you feel is being transferred from the light bulb. We will study three different types of heat transfer: Radiation - The transfer or energy without the movement of matter Conduction - Direct collisions of particles Convection - Transferred by fluids, the warm fluid flows from place to place transferring heat energy as it goes

16. Sources of Thermal Energy There are 7 sources of thermal energy we will study in this topic : Chemical Energy - Thermal Energy from burning wood Electrical Energy - Hydroelectric dams and generating stations (where there is no water) Mechanical Forces - Heat from a push or pull Geothermal Energy - Energy from the earth ( volcanoes, geysers,hot springs) Solar Energy - Energy from the sun Wind Energy - The energy from moving air Fossil Fuels - Chemicals from plants and organisms that decompose over millions of years

17. Conserving Our Fossil fuel Resources There are so many disadvantages to burning fossil fuels, but we still use them. Fossil fuels form a key part of Alberta’s economy. Coal is burned in generation stations to produce about eighty percent of the province’s electrical energy. Other fossil fuels like oil and natural gas are available in Alberta. There are many ways to conserve energy such as programmable thermostats . Refrigerators and air conditioners both have thermal energy movers. THIS A DEVICE THAT TRANSFERS THERMAL ENERGY FROM ONE LOCATION TO ANOTHER LOCATION AT A DIFFERENT TEMPERATURE. The operation of a refrigerator and an air conditioner depends on the processes of evaporation and condensation. They use refrigerants (liquids that evaporate easily at low temperatures to remove heat).