1. Kinetic theory and temperature

2. Kinetic Theory
Kinetic Theory: all particles of matter are in constant motion
Kinetic energy: the energy that comes from an object’s motion.
The more kinetic energy a particle has, the faster it moves.

3. Temperature
The temperature of a substance is a measure of the average kinetic energy of its particles.
The higher the temperature, the faster the particles move
The SI unit for temperature is the Kelvin (K)
K = °C + 273

4. Thermal Energy and heat
In addition to having kinetic energy due to their movement, objects have potential energy
Potential energy is energy due to the distance between two objects that are attracted to each other
When you lift a weight high off the ground, it gains potential energy
The sum of the kinetic and potential energies of all particles in an object is the thermal energy of the object
Heat is the flow of thermal energy from something at high temperature to something at low temperature

5. Specific Heat
The amount of thermal energy needed to raise the temperature of 1 kg of some material by 1 degree Celsius is called the specific heat
In simpler terms, specific heat measures how easy or difficult it is to change the temperature of some material
Water has a very high specific heat, so it takes a lot of energy to change the temperature of water
We measure specific heat with a calorimeter

7. States (phases) of matter

8. 3 Common states of matter on Earth
Solid
Definite shape and volume
Liquid
Definite volume but not shape
Gas
No definite shape or volume

9. Other state of matter: Plasma
Plasma exists at extremely high temperatures
Makes up 99% of the matter in the universe, but is nearly nonexistent on Earth

10. Why does matter exist in different phases?
There are attractive intermolecular forces between all particles of matter
The forces try to hold matter together in rigid formations (solid state)
The only way some matter is able to remain liquid or gas is because of its kinetic energy, or speed

11. The battle between intermolecular forces and kinetic energy
Intermolecular forces try to keep the particles together in tight, orderly formations
The particles have kinetic energy, which tries to keep them moving around
Whichever of these forces is stronger determines the state of matter

12. Phase changes

13. Heating curve for water

14. Phase changes Solid to liquid: melting (or fusion)
Liquid to solid: freezing

15. Phase changes Liquid to gas: vaporization
Below Boiling point = evaporation
At boiling point = boiling

16. Phase changes
Gas to liquid: condensation

17. Phase changes
Solid to gas: sublimation

18. Phase changes
Gas to solid: deposition

19. Vaporization: either boiling or evaporation
When vaporization occurs at the boiling point, we call it boiling
When vaporization occurs below the boiling point, it is evaporation
Boiling occurs throughout a liquid
Evaporation only occurs at the surface
The boiling point of a liquid can be lowered by increasing the pressure of air pressing down on it

20. Phase Changes
Temperature does not change during a phase change

21. Heating curve for water

22. Exothermic and endothermic phase changes
Endothermic changes absorb heat
In order for molecules to speed up and break formation, they must grab heat from their surroundings
Exothermic changes release heat
In order for molecules to slow down, they must dump heat into their surroundings

23. Exothermic or Endothermic phase change?
Freezing…………..
Melting…………….
Vaporization………
Condensation…….
Sublimation………
Deposition………..

24. Gas Laws

25. Pressure Pressure is the result of a force distributed over an area
In a gas, pressure comes from collisions between particles and the wall of the container

26. Units of Pressure Newtons per square meter (N/m²)
One N/m² is called a pascal (Pa)
We often use kilopascals (kPa, 1kPa = 1000 Pa)
Standard atmosphere (atm)
1 atm = 101,325 Pa or kPa

27. Factors that affect gas pressure
Number of particles
Increasing the number of particles of gas will increase its pressure if volume and temperature are constant
Temperature
Increasing the temperature of a gas will increase its pressure if the number of particles and volume are constant
Volume
Decreasing the volume of a gas will increase its pressure if the number of particles and temperature are constant

28. Charles’ Law Jacques Charles, 1780
Published by Joseph Louis Gay-Lussac in 1802

29. Charles Law
Note: Temperature must be in kelvin
K = ºC + 273

30. Absolute Zero
William Thomson
“Lord Kelvin”

31. Boyle’s Law
Robert Boyle, 1662

32. Boyle’s Law

33. The Combined Gas Law
Note: Temperature must be in kelvin K = ºC + 273

34. Heating Curve of Water

35. Heating Curve of Carbon Dioxide