Properties of Matter

1. Properties of Matter Unit 2 – Lecture 1 “Luminous beings are we, not this crude matter!” -Yoda, on the nature of The Force

2. Matter • Matter: anything that has mass & takes up space • The only things which truly exist in the universe are: • matter • energy

3. Properties of Matter • Physical Properties • what an object “is” [a description of a material] • ex: size, color, mass, etc.

4. Properties of Matter – cont. • Physical Changes • any change to the material that does not change the material itself • change deals with the state/phase of the matter • are REVERSIBLE • ex: icewatersteam; salt dissolved in water

5. Properties of Matter – cont. • Chemical Properties • what an object “does” • become evident during a chemical reaction • ex: (in)flammability, chemical stability, pH…etc.

6. Properties of Matter – cont. • Chemical Changes – aka Chemical Reactions • result in one or more new substances • [new substances have – of course – different chem & physical properties than original substance] • results in a change of energy • ex: acid + water gives off heat • NON-REVERSIBLE [except through another chem. rxn]

7. Properties of Matter – cont. • Obvious signs of a Chemical Change/Reaction • color change • energy released [heat, light, etc] • odor • gas(es) or solid(s) produced • …etc.

8. Practice Is each a: physical property, physical change, chemical property, or chemical change? ice melting hydrogen & oxygen making water a car is blue iron ore can be melted to obtain pure iron a screw on the deck rusts

9. Ways to Classify Matter • Composition • Based on what types of particles make up a substance • Elements, Compounds, Mixtures • Phase/State of Matter • Based on how particles are arranged because of Energy • Solid, Liquid, Gas, Plasma

10. Phases of Matter - Solids • Solids • crystal lattice: repeating pattern of particles that are locked into shape • melting points are influenced by strong forces between elements of this structure

11. Solids – cont. • Particle Movement • particles vibrate around the arranged atoms with low energy

12. Solids – cont. • Hardness • describes how hard a solid is compared to other solids • is influenced by forces betweenparticles in a solid Talc: 1 Quartz: 100 Topaz: 200 Diamond: 1600

13. Solids – Shape &Volume • shape and volume are defined – not dependent on the size or shape of container • must add energy to change shape or volume • amorphous solids – solids that change shape when energy is applied, but retain their shape w/o added energy • “a-” – non/not [negative prefix] • “morph-” – form, shape • EX: wax, glass, playdoh

14. Phases of Matter - Liquids • Liquids • Particles are touching, but not locked in pattern • Particles can “slide” past one another, causing the liquid to flow

15. Liquids • Viscosity • describes how well a liquid flows • high viscosity = “thick”; low viscosity “thin” • based on attractive forces between the particles Which is more viscous??

16. Liquids – Shape & Volume • Shape & Volume • take the shape of their container • volume is defined – not based on the size or shape of container • Surface of a liquid is assumed to be parallel to the surface of the Earth when at rest • Amorphous solids are also classified as “super-cooled liquids”

17. Phases of Matter - Gases • Gases • particles are not locked into a pattern and rarely come into contact with each other – very spread out • collisions define the pressure of the gas

18. Gases • Particle Movement • particles move almost independently in almost straight lines with higher energy than liquids – not fixed • only brief interaction when collision occurs

19. Gases – Shape & Volume • Shape & Volume • change shape & volume based on container • this is why aromatics/perfumes will spread across a room

20. Phases of Matter - Plasma • Plasma • very similar to a gas, but particles collide with so much force, electrons are knocked off of atoms • creates a “charged gas” state • uncommon on Earth; they start around 5000 ºC • only in lightning, aurorae

21. Gases • Particle Movement • movements similar to gases but with MUCH higher energy – not fixed

22. Gases • Shape & Volume • change shape & volume based on container

24. Practice Which is the lowest energy phase of matter? Which is the highest energy phase of matter? In which phase of matter are particles sliding past one another? Which phase of matter is rarely found on Earth? In which phase of matter are particles locked in a regular, repeating pattern?

25. Phase Changes • You must add or remove Heat Energy to change from one phase to another

26. Warming up! • Three Phase Changes that require added heat energy: • Melting • Going from Solid Phase to Liquid Phase • Vaporization • Going from Liquid Phase to Gas Phase • Sublimation • Going from Solid Phase to Gas Phase

27. Cooling down! • Two Phase Changes that require removalof heat energy: • Condensation • Going from Gas Phase to Liquid Phase • Freezing • Going from Liquid Phase to Solid Phase

28. Plateaus exist while matter is changing from one form to another until all matter is converted.