1. Chemical and Physical Properties of Matter
Science Survey
Chemical and Physical Properties of Matter

2. Matter Matter is anything that has mass and takes up space.
Chemistry is the study of matter and how it changes.

3. 2Classifying Matter
Pure substance (substance) – matter that always has exactly the same composition
Ex. Table Salt, Table Sugar
Every sample has the same properties due to a fixed, uniform composition.

4. Element – substance that contains only one type of atom, cannot be broken into simpler substances
Atom – smallest particle of an element
Ex. – Carbon, Oxygen, Nitrogen, Gold, Silver, Calcium, etc.

6. Matter: Compounds
A substance made of atoms of more than one element bound together is a compound. Ex) water, NaCl
Every compound is unique, and is different from the elements it contains.
Elements and compounds are pure substances

7. Matter: Compounds, cont.
The smallest unit of a compound that exhibits all of the properties of that substance is a molecule.
Chemical formula- the chemical symbols and numbers indicating the atoms contained in a molecule of a substance

8. Mixtures – composition is not fixed, properties may vary
Ex. Salsa, spaghetti sauce, sand, salad dressing, salt water
Heterogeneous Mixtures – parts are noticeably different from one another
Homogenous Mixtures – substances are so evenly distributed that it appears to contain only one substance

9. Heterogeneous Homogeneous

10. Solutions, Suspensions, Colloids
Solution – formed when substances dissolve and for a homogeneous mixture; particles are too small to settle
Suspension – heterogeneous mixture that separates into layers over time; larger particles
Colloids – contain intermediate sized particles; do not separate into layers; particles scatter light

11. States of Matter
solid - definite shape and volume, particles are close together in fixed positions.
liquid - definite volume, indefinite shape. Particles are close together, but can still slide past each other. Liquids take the shape of their container.
Viscosity is the resistance of a fluid to flow. For example, syrup is more viscous than water.

12. States of Matter, cont.
gas - neither definite shape nor definite volume; particles are far apart. Gases are free to move in all directions.
plasma- high temperature state of matter where atoms lose their electrons. Plasma is found in fluorescent bulbs, lightning, and stars.
**The forces holding solids together are stronger than the forces holding liquids together. The forces holding gas particles together are the weakest.

13. Phase Model for Water

14. Kinetic Theory and States of Matter
Energy of motion is kinetic energy. The kinetic theory says that all atoms are in motion.
Increasing temperature causes particles to speed up. Decreasing temperature slows them down.
At the same temperature, heavier particles move slower than lighter particles.
Matter can change states if the movement of the molecules changes.

15. Changes of State Energy is the ability to change or move matter.
Energy is needed for matter to change state, such as from a solid to liquid, or from liquid to gas.
Endothermic processes require added energy, while exothermic process release energy to the environment.
Evaporation is the change of a substance from a liquid to a gas.
Condensation is the change of a gas to liquid form.
Sublimation is the change of a solid directly to a gas.

16. Endothermic and Exothermic changes of State

17. Laws of Conservation
Changing the state of matter does not change its composition or mass.
Law of Conservation of Mass- Mass cannot be created or destroyed.
Law of Conservation of Energy- Energy cannot be created or destroyed.
Mass and energy can change forms. For example, when an ice cube melts, the mass of liquid water is the same as the mass of the ice cube.

18. Chemical properties
Chemical property- the way a substance reacts with others to form a new substance with different properties.
Examples: Gasoline is flammable.

19. Physical properties
Physical property- a characteristic of a substance that can be observed or measured without changing the composition of the substance.
Examples: shape, color, odor, texture, boiling point, density

20. Comparison of Chemical and Physical properties

21. Physical Properties Viscosity – a liquid’s resistance to flowing
The greater the viscosity, the slower the liquid flows and vice versa
Conductivity – a material’s ability to allow heat to flow
Malleability – ability of a solid to be hammered without shattering

22. Physical properties: Definitions
Boiling point- temperature at which a liquid becomes a gas below the surface. Water boils at 1000 C and freezes at 00 C.
Freezing point- the temperature at which a liquid becomes a solid.
Melting point- the temperature at which a solid becomes a liquid.

23. Chemical Changes
Chemical changes occur when a substance changes composition by forming one or more new substances.

24. 2.3 Chemical Properties
Flammability – ability to burn in the presence of oxygen

25. Reactivity – how readily a substance combines chemically with other substances
Ex. Rust forms when iron reacts with oxygen
and water

26. Recognizing Chemical Changes
Three types of evidence for chemical change
Change in color
Examples:
Jewelry tarnishing
Bananas turning black

27. Production of a Gas – bubbling, fizzing

28. Formation of a Precipitate
Precipitate – solid that forms and separates from a liquid mixture

29. Physical Changes
Physical change- A change in the physical form or properties of a substance that occurs without a change in the identity of the substance.

30. Physical changes, cont.
Dissolving a substance in solution is a physical change, such as dissolving a solid in a liquid or a liquid in a liquid.
Changes of state, such as melting, evaporating, boiling, condensing, and freezing are all physical changes.

31. Braiding hair is a reversible phys. change
Cutting hair is a phys. Change that is not reversible