States of Matter Density Buoyancy Viscosity NOTES!!!

1. States of MatterDensityBuoyancyViscosityNOTES!!!

2. What is Matter? • Anything that has mass and takes up space • So pretty much anything you can imagine – from the air we breathe, to water we drink, to the sun and all the stars.

3. 4 States of Matter • Solid • Liquid • Gas • Plasma

4. Solid State • Lowest energy form of matter • Molecules do not change position • Definite Shape • Definite Volume

5. Liquid State • Molecules can move around each other • Definite volume • Takes shape of container

6. Gas State • Molecules move freely and separate from one another • No definite shape • No definite volume

7. Plasma • Most common state of matter (in universe) • Highest energy form of matter • Made up of ionized gas molecules (atoms breaking apart due to high heat/energy)

8. DENSITY

9. Two Ways to Measure Matter.. • Mass • Volume

10. Density is.. • A property that relates mass and volume (combines them) • Density = mass/volume • OR • Density equals mass per unit volume (g/cm3)

11. Density affects… • Hardness (resistance to scratching) • Elasticity (ability to stretch and return) • Brittleness (likelihood to shatter) • Malleability (ability to made into thin sheets) • Tensile Strength (how much force before breaking)

12. Density of Fluids • Tend to be less dense than solids • Molecules move around each other • Do not “stack” easily • Water is an exception – ice is less dense than water (due to structure of water)

13. Density Math • The density of a material can be determined by dividing the mass by the volume • Ex. What is the density of a 400 g block that has a volume of 16 cm3? • Answer: 400/16 = 25 g/cm3

14. Conversions • Sometimes the mass is given in a unit other than grams. • Or the volume is given in a unit other than mL. • Ex. What is the density of a block that weighs 2.5 kilograms and has a volume of 40 cm3? • The mass must be converted into grams (g) • Answer: 2500/40 = 62.5 g/cm3

15. Turning things around • If you are given the density and volume of a substance, you can determine its mass. • Ex. What is the mass of a block that has a density of 3 g/cm3 and a volume of 40 cm3? • D=m/v, re-arranged, m=Dv • Answer: 3 X 40 = 120g

16. Turning things around.. Again.. • The same can be applied to volume.. • D=m/v, re-arranged, v=m/D

17. Note… • A cm3 is equivalent to a mL. Specifically, mL is used for volume of gasses and liquids and cm3 is used for the volume of solids.

18. BUOYANCY

19. Definition • The measure of upward pressure a fluid exerts on an object

20. Buoyancy is… • Determined by density • The denser the fluid, the more buoyant force it applies • Ruled by Archimedes’ Principle • The force exerted on an object by a liquid is equal to the mass of the fluid displaced by that object

21. Displaced • To move something from its usual place

22. Therefore… • If buoyant force is greater than the mass of the object, the object FLOATS • If buoyant force is less than the mass of the object, the object SINKS

23. Neutral Buoyancy • Is achieved when the mass of the object is EQUAL to the mass of the liquid displaced by that object. • The object floats exactly in the position it is placed.

24. VISCOSITY

25. Definition • Measure of a material’s resistance to flow (how hard it is to pour)

26. Viscosity is determined by… • Size of liquid molecules • Shape of liquid molecules • Temperature of liquid

27. Therefore… • A thick substance is described as being very viscous • Ketchup, syrup (cold) • Motor oils have different grades based on viscosity (10W-40, 10W-30)