Heat Transfer
What is Conduction
The direct transfer of heat from one substance to another substance that is touching
What is heat?
Heat is a form of energy that flows from a hotter object to a cooler one.
What is surface tension?
Surface tension is like a tight, elastic "skin" on the surface of a liquid, caused by the liquid molecules pulling on each other.
What do molecules look like in the following states of matter:
-Solid
-Liquid
-Gas
Solid: tightly packed in an organized pattern
Liquid: slightly spread out in a disorganized pattern
Gas: rapidly moving and spread out in a disorganized pattern
What is adhesion?
Adhesion is the attraction of molecules of one kind for molecules of a different kind
What is Convection
The transfer of heat by the movement of fluid or gas
What is temperature?
Temperature is a measure of the average kinetic energy of the particles in a substance.
When you heat ice, it melts and changes from a solid to a liquid because it gains___________
Thermal energy
In the gas phase of water (called steam or water vapor), the rapid movement resulting from elevated ____________ energy forces the molecules to expand and apply pressure on the walls of any container holding them.
kinetic
What is cohesion?
Cohesion refers to the attraction of molecules for other molecules of the same kind
What is Radiation
The direct transfer of energy by electromagnetic waves
We can measure temperature using the 3 main methods ___________________
We can measure heat using the 2 main methods _______________ *** bonus if you can get the 3rd
Temperature: Celsius, Kelvin, Fahrenheit
Heat: Joules, Calories ** bonus: kilocalories
Name 4 physical properties of matter
(Answers May Vary)
Shape
Volume: the amount of space something occupies
Density: how much mass is is packed into a certain amount of volume
State of matter
Texture
We see the ________ organization of water molecules as we go from solid to liquid to gas phases.
decreasing
________ is responsible for surface tension, the tendency of a liquid’s surface to behave like an elastic sheet
Cohesion
Drying your hands underneath a hand dryer is an example of ________
A microwave warming up food is an example of _____
A lava lamp is an example of _____
1. Radiation 2. Radiation 3. Convection
If you place a hot cup of coffee in a cooler room, the _______ will transfer to the surrounding air, causing the coffee's _______ to decrease and the room's temperature to increase until both reach the same __________.
Heat, temperature, temperature
Name 1 thing adding thermal energy can do
Name 1 thing removing thermal energy can do
Answers may vary
Adding
Increase particle movement
Cause expansion in solids, liquids and gases
Change the state (solid → liquid → gas)
Removing:
Slow particle movement
Cause contraction ( decrease in size or volume)
Change the state ( gas → liquid → solid)
Molecules in water ________ each other
At the surface, they pull forward, this creates __________
1. attract 2. tension
Give an example of Surface Tension
Answers May Vary
Explain how grilling food uses both conduction and convection *** bonus if you can add radiation
Conduction: grill grates transfer heat directly to the food
Convection: Hot air and smoke circulate around the food
Radiation: Electromagnetic waves from the glowing charcoal or flames heat the food
Temperature is related to average kinetic energy of ________
Heat is related to total ___________ transferred
1. particles 2. energy
the metal ball changed when it was heated... this is known as ________ It couldn’t fit through the ring because it expanded with increased thermal energy. When the ball was cooled.. this is called ________
expansion, contraction
Evaporation: _____ —-> _____
Condensation: _____ —-> ______
Melting: ______ —> ________
Freezing: ______ —-> ______
Evaporation: Liquid —-> Gas
Condensation: Gas —-> Liquid
Melting: Solid —> Liquid (heat added)
Freezing: Liquid —-> Solid (heat removed)
Give an example of Adhesion and Cohesion
Answers May Vary