January 21, 20151. Roll

2. PowerPoint titled:

Temperature Chapter 9, Section 1 (Distributors: pass out notes)

3. Possible Video “Exploring Heat”

Please enter the class, get your science notebook out, and sit

quietly with your hands on top of the table with your thumbs up!

You might get tickets!!!

Living Wise workbooks are due this Friday!!!!

Subject Area: Temperature

EQ: Why is Hot and Cold not a way to measure temperature?

Questions:

1. How does temperature relate to kinetic energy?

2. How is temperature different on the many temperature scales?

Temperature

Your water knobs are labeled (H) hot and (C) for cold. When you first turn on the hot knob the water doesn’t come out immediately hot. It is sometimes cold or warm. The term hot and cold are not scientific terms. If you want to specify how hot or cold something is, you must use temperature.

What is Temperature?

Temperature is the measure of the average kinetic energy of the particles in an object. Kinetic energy is the energy of motion. Hot and cold is a matter of perspective. Hot and cold for one person could be different for another. To be more accurate you must use temperature.

Temperature depends on the Kinetic energy of Particles

All matter is made of particles, atoms or molecules, which are in constant motion. The faster particles move the more kinetic energy they have.

Temperature is an Average Measure

Particles of matter are constantly moving, but they don’t all move at the same speed and in the same direction all the time. When you measure the temperature of an object you are measuring the average kinetic energy for the particles in the object.

Partner Question:What is temperature?Temperature is …

The temperature of a substance is not determined by how much of the substance you have. Substances of different amounts can have the same temperature. The total kinetic energy of the particles in each amount is different.

Temperature is an Average Measure

Measuring Temperature

How would you measure the temperature of a steaming cup of hot chocolate?

Stick your finger in it!

Sip the hot chocolate!

Pour it on your hand!

Use a thermometer!

Using a Thermometer

Many thermometers are thin glass tubes filled with a liquid. Thermometers can measure temperature because of thermal expansion. Thermal expansion is the increase in volume of a substance due to increase in temperature.

80* 120* 180*

movie

Thermal Expansion

As a substance gets hotter, its particles move faster. The particles themselves do not expand, they just spread out and the entire substance expands. When you place a thermometer in a substance, the liquid in the thermometer expands and rises.

Partner Question:What is thermal Expansion?Thermal expansion is …

Temperature Scales

Temperature can be expressed according to different scales. The same temperature will have different readings on different scales.

When you are given a temperature reading in a weather report it is more likely to be in Fahrenheit. 32°F is the freezing point of water and 212°F is the boiling point for water.

Fahrenheit

In science, the Celsius scale is used. The Celsius scale is divided into 100 equal parts called degrees Celsius. 0°C is the freezing point for water and 100°C is the boiling point for water.

Celsius

KelvinKelvin is divided into units called Kelvins (K), not

degrees Kelvin. The lowest temperature on the Kelvin scale is 0 K, which is called absolute zero. It is not possible to reach a temperature lower than absolute zero. Absolute zero is when all molecule motion has stopped.

Partner Question:What is coldest temperature possible?The coldest temperature possible is …

Partner Question:What are the three scales used to measure temperature?The three scales are …

Comparison

The freezing point of water is 32°F, 0°C, or 273 K. 0°C is much higher than 0 K. These can be converted.

Celsius to Kelvin --------------- K = °C + 273

Kelvin to Celsius ---------------- °C = K – 273

Celsius to Fahrenheit ------- °F = (1.8 x °C) + 32

Fahrenheit to Celsius ------- °C = .56 x (°F – 32)

More about Thermal Expansion

When you go over a bridge on a highway you will sometimes hear a bump. This is the expansion joints that are placed there so the bridge will not buckle when the substance that the bridge is made, expands.

Thermal ExpansionThermal expansion occurs in a

thermostat, the device that controls the heater in your home. There is a bimetallic strip in the thermostat. Because different material will expand more than others, the strip will coil and uncoil in response to temperature changes. This will open and close a circuit that will turn on and off your heater.

“Exploring Heat”What did you know?1. ________________________________2. ________________________________3. ________________________________What did you learn?1. ________________________________2. ________________________________3. ________________________________What do you want to know?1. _________________________________2. _________________________________3. _________________________________

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