Unit 2 Flashcards
Temperature
Average kinetic energy per molecule (speed pee molecule)
Heat
Flow of thermal emergency from hot to cold
Flow of kinetic energy from one molecule to another
First law of thermodynamics
Energy can’t be created or destroyed only converted or transferred from one form/place to another
Rule two of thermodynamics
Heat energy flows from high temperature to low temperature areas only
Thermal equilibrium
No net flow of heat emergency because all areas are same temperature
(Putting in as much as taking out)
Passes back equally
How does a thermometer work
Molecules of alcohol speed up and expand or slow down and contract
What causes the red line I a thermometer to stop moving
Thermal equilibrium between thermometer and water causes it to stop moving
What is temperature measured in
Celsius, C
What is heat measures in
cal. c.
What is one calorie
The amount of heat needed to raise the temp of one military of water
1 ml H2O by 1 degree
What are the calories in your food
Calories, actually kilocalories
Amount of heat needed to warm up 1,000 ml of water by one degree
High specific heat
More heat energy needed to increase the temp of some substances
Thermal energy
Total energy in molecules of a substance
A) kinetic energy of movie molecules
b) potential energy stored in chemical bonds
What cases phase change
Heat transfer
Phase change:
Change in amount of thermal energy cause molecules to move in different ways
Higher energy
Weaker intermolecular forces, mass does not change but density does
Conduction
Objects touch, direct heat transfer molecule to molecule
Convection
Heat transferred by flowing molecules
Warm fast moving molecules rise carrying heat with them, they expand and become less dense
Radiation
Electromagnetic waves , infrared radiation, no molecules
What direction does heat energy always flow and what law
Law of thermodynamics
Heat energy flows from high temperature to low temperature areas only
What is absolute 0
No motion of particles
0 Calvin
Why are metals good conductors
Because the electrons are loosely held (can flow)
Why are non metals poor conductors
Hold their electrons tightly so are poor conductors
Why do good conductors feel cold
At room temp feel cold evaluate heat is leaving your body quickly
Why are poor conductors not as cold
Because heat is leaving slower
If an object has a high specific heat capacity
It takes longer to heat up
Sublimation
Solid to gas
Deposition
Gas to solid
Gas to liquid
Condensation
Liquid to gas
Vaporization
Solid to liquid
Melting
Liquid to solid
Freezing
Solids
Vibrate in place and are closely compacted
Liquid
Particles can flow
Are spread out
Gas
Particles can flow and expand
Distance is big between particles
Where is the phase change on a graph
When it goes horizontal
Potential energy is: on a graph
The horizontal parts
Kinetic energy is: on a graph
The climbing parts /
Where is condensation in a graph
Where there is boiling
Where is crystallization on a graph
Where there is melting
The higher energy —– the intermolecular forces
Lower intermolecular forces