10. Viscosity: Thick or Thin?
Chapter 4

11. Fluids
Have the ability to flow
Are liquids or gases

12. States of matter and the Particle Theory.
The five major points of the particle theory of matter are:
Copy the points down from your textbook on page 111

13. Substances are made up of particles
Substances are made up of particles. The state of the substance depends on the arrangement of the particles.
The Three States of Matter
Gas
No attraction between particles
Far apart
Random arrangement
Vibrate
Move quickly in all directions
Solid
Particles held tightly
Very close together
Regular arrangement
Vibrate
Can’t move from place to place
Liquid
Particles held weakly
Very close together
Random arrangement
Vibrate
Constantly move past each other

14. States of Matter: Solid Liquid Gas Definite Shape Definite volume
Ex.:
Liquid
No Definite shape
Ex. :
Gas
No definite shape
No definite volume

15. Changes of State Gas Solid Liquid condensation sublimation
vaporization
sublimation
melting
Solid
Liquid
freezing

16. Two examples of vaporization are
Evaporation ( slow vaporization)
Boiling (rapid vaporization)
What is the difference between vapor and gas?
 vapor is a liquid at room temperature.
 gas is a gas at room temperature.
An example of sublimation is frozen carbon dioxide. ( Dry ice)

17. Assignment: Look and skim through Pg. 110-116 BLM 4-1, 4-3,4-9
Use the particle theory to explain why ice cubes form in your freezer.
p. 110 At Home Activity (BLM 4-4)

18. Viscosity lab reminders
Time 1:30:16 1 minute, seconds
 60 s s = sec.
Flow rate cm/sec 10cm ÷ sec = cm/s
( use 3 decimal places)
Average  Sum of trials / number of trials
( ) ÷ 2 = cm/s
Ranking  flow rate : 1-fastest slowest
viscosity : 1- thickest 4- thinnest.

19. Flow Rate and Viscosity.
Flow rate : How fast a fluid flows from one point to another. It’s measured in cm/s.
Viscosity: resistance to flow
A fluid with a high flow rate (runs quickly) has a low viscosity. (thin)

20. Flow Rate
A liquid with a low flow rate (runs slowly) has a high viscosity. (thick)
This is an inverse relationship. ( )

21. Viscosity Viscosity: resistance to flow High viscosity is thick
Low viscosity is thin
Viscosity affects the value of products (ex.medicine, food, paints)
(Read this section in your text! pg )

22. Factors that affect Viscosity:
In liquids:
Size and shape of particles (bulkiness) affect viscosity. Larger and bulkier particles will increase viscosity.

23. Factors that affect Viscosity:
Internal friction (particles rubbing on each other) affects viscosity.
Ex. Water particles move past each other easily but honey particles have more internal friction and do not move past each other as easily as water.

24. Factors that affect Viscosity
Temperature:
Viscosity decreases as a fluid is heated and viscosity increases as the fluid is cooled.
This is an indirect relationship.

25. Factors that affect viscosity Continued…
In gases:
Size and shape of particles:
Larger and bulkier particles increase viscosity.

26. Temperature and Internal friction
High temperatures increase internal friction because the particles speed up and collide more frequently-therefore increase viscosity
Cool temperatures keep internal friction and viscosity low.

27. Translation
For gases,
Viscosity increases as temperature increases and viscosity decreases as temperature decreases.
It is a direct relationship.

28. Assignment: Read p. 118 – 119 (lab – flow rate)
BLM 4-13(3only) , 4-23, 4-17
Pg CYU 1-4