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Science8_Ch7_2013_Teacher .notebook
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Oct 67:20 PM
Grade 8 Science
Chapter 7Unit 2: Fluids & Viscosity
Oct 67:31 PM
Key Terms
* Boiling
* Boiling Point
* Flow Rate
* Fluid
* Gas
* Liquid
* Melting
* Melting Point
* Solid
* Solidification
* Viscosity
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Science8_Ch7_2013_Teacher .notebook
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October 25, 2013
Oct 67:44 PM
The Particle Theory of Matter (PTM)
A REVIEW (Page 270)
All matter is made up of very tiny particles.
All particles in a pure substance are the same but different
from another substance.
There is space between the particles.
The particles are always moving. They move faster if they gain
energy.
There are attractive forces between the particles. Some strong;
some weak.
Oct 67:57 PM
Recall the 3 states of matter: State Shape Volume
Particle Arrangement
Particle Movement
Solid Definite Definite Close Vibrate
Liquid Indefinite Definite Close Free Flowing
Gas Indefinite Definite Far Apart Random
http://www.youtube.com/watch?v=s‐KvoVzukHo
Book Work: Page 272 #'s 1‐5
Page 277 #'s 1, 4, 7 & 8
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Science8_Ch7_2013_Teacher .notebook
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October 25, 2013
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Any form of matter that flows
Liquids & Gases are fluids.
Since liquids & gases do NOT have a definite shape they are
able to flow making them fluids.
Solids are NOT fluids. They have a definite shape.
Fluids
We use fluids everyday...Food fluids (Water, oil, maple syrup,
honey, etc...)Cleaning fluids & creams (Water).Bodily fluids
(blood).Industrial fluids (compressed air in tires, lubricants,
etc...)
Oct 68:31 PM
A measure of a liquid's resistance to flow. The thickness or
thinness of a fluid.
A fluid that is viscous is the one that is NOT "runny" (flows
slowly).
Friction resists movement.
The greater the friction, the greater the viscosity.
The particles are holding on tightly to each other.
Viscosity
Viscosity & Friction
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Science8_Ch7_2013_Teacher .notebook
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October 25, 2013
Oct 78:59 PM
Different fluids have different flow rates or vicosity.
Many substances require the proper degree of viscosity to
perform their intended function.
Example: The thickness or thinness of our pancake batter or
motor oil in our skidoos.
Viscosity is important in everyday life!
Oct 79:15 PM
Flow Rate
The speed at which a fluid flows from one point to another.
Viscosity Flow Rate Description
High Slow Thick
Low Fast Runny
Example:
Slow Medium Fast
Corn Syrup Dish Liquid Water
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October 25, 2013
Oct 2510:28 AM
Core Lab Activity 7‐2B
The Flow Rate of Liquids
Page 282‐283
Read through the procedure section of the lab!
Oct 79:25 PM
Factors That Affect Viscosity:
1) Temperature:As you increase temperature, you decrease a
fluid's viscosity. As you decrease temperature, you increase a
fluid's viscosity.
Example: As the temperature of molasses is increased it flows
faster: Low viscosity.
As the temperature of cooking oil is decreased it flows slower:
High viscosity.
The OPPOSITE is true of gases!
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October 25, 2013
Oct 79:38 PM
2) Concentration:The amount of a substance dissolved in a
specific volume.
Increasing the concentration, increases the viscosity.
Example:Skim milk 1% milk 2% milk whole milk cream
3) Attractive Forces:If the attractive forces are strong, it is
difficult for the particles to pull away, therefore the fluid flows
slowly and is more viscous.* attraction of particles within the
liquid* attraction between particles of the liquid and the
particles of the object on which it is flowing. (stick to each
other & stick to the container)
Oct 218:00 PM
4) Particle Size:
The smaller the particle size, the faster the fluid flows and is
less viscous.
Bookwork:Page 297: #'s 1‐9
Page 298: Checking the concepts: #'s 1, 2, 3, 5, 6, 7 a), 8, 9,
11, 12, 13, 14, 15, 16.
Core STSE: Cleaning Fluids: Soaps & Detergents
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