SJ #11 “Temperature and Density Notes”

advertisement

SJ #12 “Temperature and Density”

Lesson 5 p.43

* TEMPERATURE : the amount of ENERGY that the molecules in a substance have.

-measured with a thermometer

“therm” = heat

“meter” = measure

-EX: high temp.  fast moving,

high energy molecules

low temp.  slow moving,

low energy molecules

* HEAT : the TRANSFER of ENERGY from a hotter object to a colder object. (“transfer” means to move)

--add heat  temp. increases

--remove heat  temp. decreases p. 43 “Changing Temperature, Changing Density”

-MOST matter increases in VOLUME when it gets hotter  EXPANSION

*EX: if you heat a gas, particles will expand, but MASS STAYS THE SAME

 gas will be LESS DENSE

-MOST matter decreases in VOLUME when it gets colder, CONTRACTION

*EX: if you cool a gas, particles will contract, but MASS STAYS THE SAME

 gas will be MORE DENSE

**WATER IS AN EXCEPTION!

**H

2

O actually expands when it freezes, so it becomes less dense and floats.

**This is why pipes burst a lot in winter.

**Other exceptions: gallium, bismuth, acetic acid, antimony, and silicon, due to their molecular geometry. They form “tetrahedral lattices”, a fancy term for a kind of crystal.

*Eureka! Episodes 19, 20 & 21

*Expansion & Contraction

1)

2)

3)

*Measuring Temperature

1)

2)

3)

*Temperature vs. Heat

1)

2)

3)

+ 1 drawing

*Read p. 4445 “Measuring Temperature By Degrees”

--write 10 facts

*3 from p. 44

*7 from p. 45

*What is the most interesting idea you read in this article? Answer in a complete sentence!

Download