Welcome Back Minions!!! Time to get to work!
Hot… Cold… All relative to me… • Tell me about how the weather FEELS as of late… • Tell me about the hottest day you remember. • Tell me about the coldest day you remember.
Hot? Cold? • Is there a “HOT” or a “COLD” in science? • How do we measure “HOT” and “COLD”?
Temperature! • What is “Temperature”? • A measure of the average kinetic energy of the individual particles in matter. • Matter is made of particles always moving. The faster they move, the more kinetic energy there is, thus the greater the temperature will be. • Since we cannot measure the kinetic energy of EVERY SINGLE PARTICLE… We take a sample and find the “average”. This is Temperature.
How to measure temperature… • Thermometer! • Liquid in a glass tube. • The tube is heated, this heats the liquid inside, the liquid expands thus it moves up the tube. • The opposite is true when it is a lower temperature.
Measurement… • Three Temperature Scales • Fahrenheit • Celcius • Kelvin
Fahrenheit… • Daniel Gabriel Fahrenheit • According to an article Fahrenheit wrote in 1724, he based his scale on three reference points of temperature. • he used a mixture of ice, water, and ammonium chloride, a salt, that stable temperature was defined as 0 °F. • The second point, at 32 degrees, was a mixture of ice and water without the ammonium chloride at a 1:1 ratio. • The third point, 96 degrees, was approximately the human body temperature, then called "blood-heat".
Celcius… • Anders Celcius • The unit was known until 1948 as "centigrade" from the Latin centum translated as 100 and gradus translated as "steps". • Two different points • 0° Celcius is the freezing point of water • 100° Celcius is the boiling point of water
Kelvin • William Thomson, 1st Baron Kelvin • He wrote: • “…the need for a scale whereby "infinite cold"“. • This is absolute zero. • (Point where matter stops moving)
Review • What is temperature? • A measure of the average kinetic energy of the individual particles in matter. • What is used to measure temperature? • Thermometer • Which scale is based off of “Absolute zero”? • Kelvin • Which scale is based off of “Water Freezing”? • Celcius • Which scale is based off of the freezing of “Brine”? • Fahrenheit
Homework!!! • Read Chapter 14, section 1 • (Pages 472-477) • Make sure you have the vocabulary as well!