Science 7 Unit 3 Topics 1-4 Review Slides PDF

Using Energy From Heat Science 7 Unit 3 Topics 1 How have humans used the energy from heat throughout history? Essential Question Creation of Ancient Fireplace and Cast Iron Fire - Roman Chimneys - Stoves - 7000 B.C Central 1300s AD 1700s...

Using Energy From Heat Science 7 Unit 3 Topics 1 How have humans used the energy from heat throughout history? Essential Question Creation of Ancient Fireplace and Cast Iron Fire - Roman Chimneys - Stoves - 7000 B.C Central 1300s AD 1700s Heating - 100 B.C Coal Burning Forced-Air Electric Central Heating - Heaters - Heating - Late 1800s 1906 Late 1700s  Measuring Temperature Science 7 Unit 3 Topic 2 Review We use two of our senses to give us a relative idea of temperature. - They are: Sight & touch. We learned that the same temperature can feel different to the touch under different circumstances. Why is this? Because of relativity - our bodies become accustomed to the temperature they are in 0°C is what in Kelvins? 273.15kelvin The two main temperature scales are: Celsius & Kelvin Review What are thermometers? ○ They are are more reliable devices that measure temperature. What did Galileo Galilei do? ○ He made the first air thermometer What did Anders Celsius do? ○ The first precise scale, “degree” that was based on the properties of water. Why are scales on thermometers important? ○ So we can make consistent standard measurements of temperature. Review What did Lord Kelvin do? ○ Created absolute scale used by scientists around the world, measured in Kelvins. Why did Lord Kelvin create an absolute scale? ○ So scientists have a standard measurement to communicate with. Standard Temperatures You Must Know *at sea level Absolute Zero (the Body Room Freezing Boiling coldest Temp. Temp Point* Point* temperature Temperature -273 37 20-25 0 100 (°C) Effects of Pressure Pressure also affects the freezing and boiling points of water. - Extremely high pressure can - Low pressure enables cause ice to melt at a water to boil at a temperature temperature - below 0°C. - below 100°C. Measuring Extremes Thermometers used to measure such extreme temperatures (and regular temperatures) have three common elements: 1. A sensor: a material which is affected by changes in temperature. 2. A signal: providing information about the temperature, such as an electric current. 3. A responder: which indicates the data with a pointer, light or other mechanism using the signal. What are the 4 sensors that measures temperature. A thermocouple is two wires twisted together that, when heat is applied, create an electrical current that impacts the responder. A bimetallic coil is two fused metal strips that, when heat is applied, expand at different rates and cause the end of the coil to move, which then impacts the responder. What are the 4 sensors that measures temperature. A recording thermometer is a bimetallic coil strip that expands at different rates when heat attached to a long arm lever with a marker at the end, and a drum that has graph paper. Infrared thermography is the process where a thermal camera captures and creates an image of an object by using infrared radiation (heat) emitted from the object The Particle Model, Temperature and Thermal Energy Science 7 Unit 3 Topic 3 Particles in Different States  Particles in Different States Solids Liquids Gases Shape and Size Compressibility (volume)  Particles in Different States Solids Liquids Gases Shape and Size Keep their Take the shape of No definite shape shape and size the container or size Compressibility Cannot be Almost Can be (volume) compressed incompressible. compressed. (fixed volume) (Fixed Volume) Volume changes. Five parts of the Particle Model of Matter 1. All substances are made up of tiny particles that are too small to be seen 2. The particles have spaces between them 3. The particles are always in motion – vibrating, rotating and (in liquids and gases) moving from place to place 4. All particles in a pure substance are the same. Different pure substances are made up of different particles. 5. The particles in a substance are attracted to one another. The strength of the attractive force depends on the type of particles. Review: Temperature indicates the average energy (speed) of the particles in motion in a substance. The motion of the particles increases when the temperature increases. The motion of the particles decreases when the temperature decreases. Review: Energy is the measure of a substance’s ability to do work and cause changes. Thermal energy is the energy generated by the movement or vibration of particles; the total kinetic energy of all the particles in a substance. The Law of Conservation of Energy → energy cannot be created or destroyed, it can only be transformed from one type to another or passed from one object or substance to another Expansion and Contraction Science 7 Unit 3 Topic 4 Expansion & Contraction As the average energy of particles increases, the spaces between the particles increases. IT EXPANDS. As the average energy of particles decreases, the spaces between the particles decreases. IT CONTRACTS Expansion and Contraction in States of Matter Heated Colded Solid Expand Contract Liquid Expand Contract Gas Expand Contract Application: Civil Engineering